Synthesis

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Synthesis Example

C9H10O3 + C3H6O3 -> [CH4O +] C11H12O5
Treatment of o-hydroxyacetophenones 2a-e with excess lithium bis(trimethylsily)amide followed by dialkyl carbonates gave alkyl 3-(2-hydroxyaryl)-3-oxopropanoates 3a-e. The latter substances were transformed through the reaction of their magnesium chelate with benzoyl chlorides into a series of 3-(alkoxycarbonyl)-2-arylflavones, which were subsequently elaborated into a variety of flavonoids. These compounds were tested for their abilities to inhibit the in vitro protein-tyrosine kinase activity of p56lc , an enzyme which is though to play a key role in mediating signal transduction from the CD4 receptor during lymphocyte activation. All of the active compounds had either an amino or a hydroxyl substituent at the 4'-position of the 2-aryl ring. The most active substance prepared in this study is compound 17c, which is approximately 1 order of magnitude more potent than the natural product quercetin (1). Compound 17c was a competitive inhibitor of p56lck with respect to ATP and was highly selective for t e inhibition of protein-tyrosine over protein-serine/threonine kinases.

C21H30O3 -> [O +] C21H30O2
Reaction of 21-alkyl ethers 1, 4-6, 8, and 9 with a large excess of trimethylsilyl iodide (TMSI) produced the deoxygenated products 3 and 11 in low to moderate yields along with a small amount of 21-alcohols 2 and 10. The deoxygenation reaction in the pr sence of 1.5 molar equiv of MeOH gave the products in much higher yields than those without MeOH, except the reaction of the ethyl and n- propyl ethers 4 and 5. Treatment of 1 and 8 with trimethylsilyl chloride/NaI in the presence of MeOH gave similar re ults to those with TMSI. Compound 3 was also produced in high yields by reaction of 1 and 4 with HI under mild conditions. On the other hand, treatment of 17-alpha-ketol 7 with TMSI in the presence of MeOH yielded 17-alpha-beta-methyl D-homo steroid 15. The results along with deuterium-labeling experiments with MeOD and IR and H-1 NMR spectral analysis during the reaction with TMSI suggest that dealkylation of the 21-alkyl ethers precedes the deoxygenation, in which HI produced in situ by reaction of Me H with TMSI would be involved.

C4H8O2S + C7H8N2 [+ C9H8N2S] -> C10H12N2OS + C10H12N2OS
Two distinctive methods for the synthesis of cis- and trans-2,5-disubstituted-thiazolidin-4-ones via stereoselective cyclo-condensation between alpha-mercaptocarboxylic esters and arylimines have been developed. With the new reaction used as the key step two sets of optically active anti-PAF active thiazolidin-4-ones were synthesized.

C6H4O2 + C3H5IO2 [+ H] -> [I +] C9H10O4
Indium-mediated Reformatsky reaction of para-quinones gives good yields of para-quinols under mild conditions. Naturally occuring quinol esters such as jacaranone are conveniently prepared in a one-pot synthesis.

C5H4IN5 + C9H14N2O3 -> [C4H6N2O +] C10H12IN5O2
A series of 6-substituted 2',3'-dideoxypurine ribofuranosides (ddP) was enzymatically synthesized with live E. coli in an effort to enhance the lipophilicity of this class of anti-human immunodeficiency virus (HIV) compounds and thereby facilitate drug de ivery into the central nervous system. All 6-halo-substituted ddPs were substantially more lipophilic, as defined by their octanol-water partition coefficient (P), than their nonhalogenated congeners 2',3'-dideoxyinosine (ddI) or 2',3'-dideoxyguanosine ( dG). For this class of compounds, log P's ranged from +0.5 to -1.2 in the following order: 6-iodo, 2-amino-6-iodo > 6-bromo, 2-amino-6-bromo > 6-chloro, 2-amino-6-chloro > 6-fluoro, 2-amino-6-fluoro >> ddG > ddI. These compounds were evaluated in vitro for ability to suppress the infectivity, replication, and cytopathic effect of HIV. 2-Amino-6-fluoro-, 2-amino-6-chloro-, and 6-fluoro-ddP exhibited a potent activity against HIV comparable to that of ddI or ddG and completely blocked the infectivity of IV without affecting the growth of target cells. The comparative order of in vitro anti-HIV activity was 2-amino-6-fluoro, 2-amino-6-chloro, 6-fluoro > 2-amino-6-bromo > 2-amino-6-iodo, 6-chloro > 6-bromo > 6-iodo. These compounds also exhibited potent n vitro activity against HIV-2 and 3'-azido-3'-deoxythymidine-resistant HIV-1 variants. All 2-amino-6-halo-ddPs and 6-halo-ddPs were substrates for adenosine deaminase (ADA) and were converted to ddG or ddI, respectively. In the presence of the potent A A inhibitor 2'-deoxycoformycin, 6-halo-substituted ddPs failed to exert an in vitro antiretroviral effect. These dideoxypurine nucleoside analogues represent a new class of lipophilic prodrugs of ddG and ddI that possess the potential for more effective herapy of HIV-induced neurologic disorders.

C9H14O2 [+ C9H18O2] -> C9H16O2 + C9H16O2
Stereoselective reduction and cyclization of 6-methyl-2-propionyl-2,3-dihydro-4H-pyran provides brevicomin in quantitative yield as a 86:14 or a 17:83 mixture of exo and endo isomers through DIBAH reduction in ether at reflux or Zn(BH4)2 in the presence o ZnCl2 in ether at 0-degrees-C, respectively.

C5H10NO7P -> [C2H2O2 +] C3H8NO5P
Colbalt(II) ion has been found to catalyze the molecular oxygen driven oxidation of N-(phosphonomethyl)iminodiacetic acid (PMIDA) to N-(phosphonomethyl)glycine (PMG) in aqueous solution. 1 This homogeneous catalytic conversion is novel and represents, in effect, an oxidative dealkylation of one carboxymethyl moiety yielding the N-substituted glycine. The reaction is selective to the desired product PMG when carried out at the natural pH of the free acid substrate (approximately 1-2) and when carried out a substrate loadings less than 5% by weight. In addition, the catalytic system is selective for the PMIDA substrate; i.e., other closely related ligands show no reactivity, e.g., NTA, EDTA, etc. The results of kinetic and mechanistic studies on dilute sy tems are presented and discussed with special emphasis on how an understanding of the mechanism can make it possible to generate a catalyst system that gives high yields even with high substrate loadings. The reactions are first-order in substrate and (Co t. The oxygen pressure dependence exhibits saturation kinetics, while the selectivity increases as oxygen pressure increases. The rate is also inversely proportional to (H+). The high selectivity of the oxidation and the unique selectivity of the cobal catalytic system for the PMIDA substrate are discussed in terms of the magnitude of the metal ligand binding constant at the low pH of the reaction.

C6H14N2O2 + C8H6INO4 -> [C6H5NO3 +] C8H15IN2O3
Mild reaction conditions were developed for the preparation of the active-site-directed irreversible enzime inhibitors (+)-S-2-amino-5-iodoacetamidopentanoic acid and (+)-S-2-amino-6-iodoacetamidohexanoic acid.

C14H15NOS + C2H2Cl2O [+ H] -> [Cl +] C16H18ClNO2S
We have found that the treatment of a Schiff base (2) with trichlorosilane and chloroacetyl chloride results in a highly active chloroacetamide herbicide (1) in an excellent yield. This one-step hydroamidation reaction of a Schiff base is a useful synthe ic method.

C8H10 + C3H7Br [+ C2HO2] -> [Br +] C13H18O2
A one-pot reaction sequence consisting of three consecutive metalation and electrophilic substitution stages leads to 2-(4-isobutylphenyl)propanoic acid with 52% over-all yield. A crucial step is the alkylation of deprotonated p-ethyltoluene with isoprop l bromide. In general terms, sec-alkyl halides and benzyl or allyl type alkalimetal reagents undergo coupling reactions with surprising ease.

C3H8LiNO2S + C13H17NO [+ H] -> [Li +] C16H26N2O3S
The addition of metallated N,N-dialkyl-sulfonamides 1 to Mannich bases 2, leading to N,N-dialkylamides of 4-(N',N'-dialkylamino)-2-hydroxy-2-phenylbutanesulfonic acids (4) is described.

C18H24O2 [+ O] -> [H2 +] C18H22O3
Cis 3 and trans methyl 7-oxo-podocarpa-8,11,13-trien-15-oate 4 are synthesized in high yields by photo-oxygenation of cis 1 and trans methyl podocarpa-8,11,13-trien-15-oate 2 obtained from dehydroabietic acid.

C10H10N2OS + C6H10O4 -> [C2H6O +] C14H14N2O4S
2-Amino-4-arylthiazoles react cleanly with dialkyl oxalates in the presence of sodium alkoxides at room temperature to afford alkyl N-(4-aryl-2-thiazolyl)oxamates in high yield.

C6H5NO3 + C2H4O2 -> [O3 +] C8H9NO2
Anilides are synthesized from nitroarenes via sequential reductive N-acylation, catalyzed by ruthenium compounds in the presence of a carboxylic acid and methyl formate or formic acid. In the reduction step, hydrogen is supplied by the formic compound.

C23H43N7O8 + C25H37N7O8 + C45H70N10O12S + C22H40N6O8 ->
The peptides eglin c (41-70), eglin c (60-70), eglin c (50-70) and eglin c (45-70) have been synthesized by a conventional solution method in order to allow us to study the relationship between the structure and their inhibitory activity against human leu ocyte elastase, cathepsin G and alpha-chymotrypsin. Six relatively small peptide fragments were coupled successively from the C-terminus by the azide method to minimize racemization and to avoid the need for protection of side-chain functional groups of he amino acid residues as much as possible during the peptide synthesis. The protected peptides were treated with 1 mol dm-3 trimethylsilyl bromide in trifluoroacetic acid at 0-degrees-C for 3 h in the presence of thioanisole and m-cresol, followed by pu ification by Sephadex G-25 column chromatography and preparative reversed phase HPLC to give the desired peptides, which exhibited a symmetrical, single peak on analytical HPLC. Eglin c (60-70) inhibited human leukocyte elastase (K(i) 1.7 x 10(-3) mol dm 3) but not cathepsin G or alpha-chymotrypsin. Eglin c (50-70) and eglin c (45-70) inhibited leukocyte elastase (K(i) 2.0 x 10(-4) and 7.0 x 10(-5) mol dm-3, respectively) and alpha-chymotripsin (K(i) 3.4 x 10(-5) and 2.5 x 10(-5) mol dm-3, respectively) ut not cathepsin G. Eglin c (41-70) inhibited leukocyte elastase, cathepsin G and alpha-chymotrypsin with K(i)-values of 1.2 x 10(-5), 2.1 x 10(-4) and 7.0 x 10(-6) mol dm-3, respectively, while the K(i)-values of acetyleglin c (1-70) for the above enzyme were 5.0 x 10(-9), 1.0 x 10(-9) and 2.3 x 10(-9) mol dm-3, respectively.

C32H49N7O9 + C37H52N8O12 + C43H61N9O10 + C43H59N9O11S ->
Commencing with a protected C-terminal triacontapeptide of eglin c, eglin c (31-70), eglin c (22-30) and eglin c (8-70) and finally eglin c were synthesized by a conventional solution method in order to allow us to study the relationship between their str cture and the inhibitory activity against human leukocyte elastase, cathepsin G and alpha-chymotrypsin. Ten relatively small peptide fragments were coupled successively from the C-terminus by the azide method to minimize racemization and to avoid the nee for protection of the side-chain functional groups of the amino acid residues as much as possible during the peptide synthesis. The protected peptides were treated with HF at 0-degrees-C for 60 min in the presence of thioanisole and m-cresol to give the desired eglin c fragments and eglin c, which exhibited a symmetrical single peak on analytical HPLC. Although the inhibitory activity of eglin c (31-70) and eglin c (22-70) against the aforementioned enzymes did not increase dramatically, eglin c (8-70) xhibited inhibitory activity against the above enzymes with similar or rather lower K(i)-values than that of N-alpha-acetyleglin c. Mass spectrometry of the synthetic eglin c by electrospray ionization exhibited peaks at 1012 (M + 8H)8+, 1157 (M + 7H)7+ a d 1349 (M + 6H)6+, supporting the view that the molecular weight of synthetic eglin c (C373H550N96O107) is 8090.9 (Calc. for (M + 8H)/8 = 1012.36, (M + 7H)/7 = 1156.84 and (M + 6H)/6 = 1349.48). Furthermore, the synthetic eglin c exhibited the same inhib tory activity against human leukocyte elastase, cathepsin G and alpha-chymotrypsin (K(i) = 5.1 x 10(-9), 1.5 x 10(-9), and 2.2 x 10(-9) mol dm-3, respectively) as N-alpha-acetyleglin c synthesized genetically (K(i) = 5.0 x 10(-9), 1.0 x 10(-9), and 2.3 x 0(-9) mol dm-3, respectively).

C20H16N2O5 [+ C20H16N2O4] -> C20H16N2O5 + C20H16N2O4
20(S)-Camptothecin derivatives having nitro, amino, chloro, bromo, hydroxyl and methoxyl groups in the A-ring were synthesized. B-Ring hydrogenated camptothecin (2a) was converted into 10-hydroxycamptothecin (6e) by treatment with lead tetraacetate in tr fluoroacetic acid. 10-Substituted derivatives (6) were obtained by a photoreaction of N-oxides (9). The cytotoxicity of the A-ring modified camptothecins was evaluated against KB cells in vitro and leukemia L1210 in mice. 7-Ethyl-10-hydroxycamptothecin (6i) was identified as a potential derivative for further modification.

C33H40NO7P [+ R2] -> [C23H28O3 +] C10H12NO4PR2
A new, protected derivative of phosphonomethylphenylalanine is used to synthesize nonhydrolyzable analogs of phosphotyrosyl peptides for use as inhibitors and affinity ligands of proteins that recognize phosphotyrosyl sequences.

C13H10N2O2 [+ C2H7O3P] -> C15H17N2O5P
A convenient synthesis of dialkyl arylaminomethyl- and (arylamino)arylmethylphosphonates 3 and their N-acelated derivatives 5 have been developed, starting from azomethines and phosphorus trichloride in the presence of an alcohol.

C12H17NO3S2 [+ H2] -> C12H19NO3S2
5-Alkyl-3-carboxymethylrhodanines (2) were prepared from 5-alkylmethylidene-3-carboxymethylrhodanines (1). The exo double bond of 1 was successfully reduced with NaBH4. The 1,4-addition reaction path was confirmed on the basis of proton nuclear magnetic r sonance spectrum of the product (4b) obtained from the reduction of 3 using NaBD4. Optical resolution of the tert-butyl compound (2i) was achieved upon epimerization-crystallization method using L-3-amino-epsilon-caprolactam. The alkyl compounds (2) and t e optical active compounds ((+)-2i, (-)-2i) were evaluated for aldose reductase inhibitory potency.

C8H4Cl2N2 + C8H17N + C2H5N5 [+ C36H46N16] -> [Cl2 +] C18H24N8 + C24H36N4 + C12H12N12
A simple method for the synthesis of sweet tasting N,N',N"-trisubstituted guanidines is described. The key intermediate, carbonimidoyl dichloride 6, was prepared using a known method. Reaction of 6 with cyclooctylamine followed by the sodium salt of 5-a inomethyltetrazole or the sodium salt of glycine afforded the desired guanidine. When the carbonimidoyl dichloride was allowed to react with (S)-alpha-phenethylamine followed by the sodium salt of glycine, the guanidine sweetener 2 was obtained.

C11H13N5O3 + C44H88NO8P -> [C5H13NO +] C50H88N5O10P
A novel series of neplanocin analogues, 6'-(3-sn-phosphatidyl)neplanocin As bearing a variety of fatty acyl or alkyl residues in the glyceride moiety (2b-2h), were synthesized by means of phospholipase D-catalyzed transphosphatidylation. Among them, 2b, 2 , and 2e each exhibited significant antitumor effect against P388 leukemia in mice, which evidently surpassed that of parent compound neplanocin A.

C8H7NS + C9H11NO -> [H2O +] C17H16N2S
New 2-benzylideneimino- and 2-styryl-1,3-benzimidazole and benzothiazole derivatives have been prepared and tested in vitro against Caenorhabditis elegans, and Heligmosomoides polygyrus, showing some of them, interesting properties as inhibitors, which we e not observed in the complementary in vivo tests. In order to rationalize the activity, log P was measured for all compounds, and QSAR models were developed, allowing the optimisation of the in vitro activity.

C24H33N3O2 + C8H19N -> [H2 +] C32H50N4O2
5-Amino-5-deazaflavin derivatives are newly synthesized by direct coupling of 5-deazaflavins and amines. Some of them revealed potential activity toward tumor cells such as L1210 or KB cells.

C5H8O + C5H9Br [+ H] -> [Br +] C10H18O
Carboindation of alkynols by allylic indium sesquihalides proceeded in DMF at 100 - 140-degrees-C via a syn-addition; yomogi alcohol was prepared in one-pot by this method.

C18H22N2 [+ T15] -> [H15 +] C18H7T15N2
(G-H-3)imipramine and (G-H-3)desipramine with specific activities 110-160 and 80-100 kCi/mol, respectively were synthesized by high temperature solid-phase catalytic isotope exchange with gaseous tritium.

C14H12O3 [+ H2] -> C14H14O3
The synthesis of (R, R)DIPAMP ruthenium bis (2-methylallyl) 2 and halogeno derivative (R, R) DIPAMPRu2X2 3 complexes is presented, which uses the easily available from (COD)2Ru(2-methylallyl)2. 1. These new catalysts were found to be effective for asymmet ic hydrogenation of both olefins and keto groups (35-80% ee).

C5H4IN + C5H4BrN -> [BrI +] C10H8N2
The oxidative addition of active zinc to bromo- and iodopyridines gave pyridinylzinc halides which were coupled with aryl halide or benzoyl chloride in the presence of a palladium catalyst.

C15H26O [+ CH4] -> C16H30O
The stoichiometric conjugate addition with 60% enantiomeric excess (e.e.), of a chiral alkoxydimethylcuprate prepared from an 80:20 mixture of (1R,2R,3S,4S)-3-((1-methylpyrrol-2-yl)-methylamino)-1,7,7-trimethylbicyclo(2.2.1)heptan-2-ol (endo-(+)-MPATH-3) nd its enantiomer (endo-(-)-MPATH), to (E)-cyclopentadec-2-en-1-one 1 produced (R)-(-)-muscone 2 in 76 %e.e. and 82% chemical yield. This chiral amplification can be explained by considering that the reaction proceeds via a homochiral dimeric cluster of t e chiral alkoxydimethylcuprate. The catalytic conjugate addition was realized by adding methyllithium and the enone alternately to a toluene solution of the chiral alkoxydimethylcuprate prepared from a catalytic amount of the chiral ligand and copper(I) s lt. (R)-(-)-Muscone with 99% optical purity was obtained in 85% chemical yield by the use of 0.36 equiv. of endo-(+)-M PATH and 0.33 equiv of copper(I) iodide. This methodology provides not only the highest enantioselectivity, but also useful information n the structure and mechanism of the conjugate addition of the organocuprate prepared from the copper(I) salt and alkyllithium.

C22H28N2O7S [+ C22H26N2O7S] -> C44H54N4O14S2
Penicillin X methyl ester was transformed into three types of dimer by laccase from Coriolus versicolor. The dimers are considered to be formed by free-radical addition of phenoxy radicals produced by laccase. The enzyme reaction with the ester as substra e was more suitable for forming dimers than that with the sodium salt as substrate. Penicillin X pivaloyloxymethyl ester was also transformed into a dimer, which had antibacterial activity in the presence of esterase.

C12H16N2 + C4H6O2 -> C16H22N2O2
Cyclic amidines 4 and 11 have been shown to be in N,C-tautomeric equilibrium with the corresponding ene-1,1-diamines which can be C-alkylated by methyl acrylate, leading respectively to the corresponding functionalized substituted amidines 6 (or 7) and 12

C21H29ClO3 [+ H2] -> [O +] C21H31ClO2
Zinc reduction of alpha,beta-unsaturated ketones in acetic acid has been efficiently accomplished under sonochemical conditions. Different alpha-enone systems give two kinds of products: olefins and allylic alcohols. Regio- and stereoselectivities are rep rted.

C12H10S2 + C7H8O -> [C6H6S +] C13H12OS
In the presence of an active acidic catalyst generated from SbCl5 and AgSbF6, the sulfenylation reaction of aromatic compounds with organic disulfides smoothly proceeds in refluxing 1,2-dichloroethane to afford the corresponding unsymmetrical sulfides in igh yields.

C7H9N3O2 -> [N2 +] C7H9NO2
The intermolecular and intramolecular coupling of a cyano group with a nitro group induced by a low-valent titanium reagent prepared from titanium tetrachloride and zinc powder was studied.

C12F25NO -> C12F25NO
Perfluoro-2,3-dialkyloxaziridines rearrange at 120-160-degrees-C into R(f)N=CF-OR'f quantitatively. Reaction with SbF5 at elevated temperature leads to the formation of the isomeric alkoxy imines R(f)ON=CFR'f. Reaction with CsF in the absence of a solvent results in formation of a mixture of the corresponding acyl fluoride R'(f)C(O)F and N-fluoro imine R'(f)CF=NF. In contrast, reaction between perfluoro-2-butyl-3-propyloxaziridine and CsF in MeCN produces C4F9ON=CFC3F7. Interaction of this oxaziridine with polyfluoro ketones and COF2 in the presence of CsF in polar solvents leads to the formation of alkoxy imines R"(f)ON=CFC3F7.

C10H22O -> [H2 +] C10H20O
Treatment of a 1,2-dichloroethane solution of various alcohols with iodosylbenzene in the presence of a catalytic amount of ytterbium(III) nitrate provided the corresponding carbonyl compounds in good to excellent yields.

C8H6OS6 -> C8H6OS6
Irradiation of 4,8-dialkylbenzo(1,2-d;4,5-d')bis(1,2,3)trithiole 2-oxides (2) in acetonitrile with a high pressure mercury lamp gave 4,8-dialkylbenzo(1,2-d;4,5-d')bis(1,2,3)trithiole 1-oxides (3) quantitatively. The present photochemical oxygen migratio s of 2 and related sulfoxides were shown to proceed intramolecularly via an excited singlet state by O-18-labeled, cross-over, and triplet quencher experiments.

C4H10O2 [+ C4H8O3] -> C4H10O2 + C4H8O3
(S)-3-Hydroxybutyric acid and (S)-1,3-butanediol were obtained by the treatment of 1,3-butanediol with the resting cells of methanol yeast, Candida boidinii (IFO 10574). (R)-1,3-Butanediol was also obtained in high optical purity by the enantioselective r duction of 4-hydroxy-2-butanone in the presence of methanol using the same methanol yeast.

C10H11O5P + C5H10O [+ C11H7] -> [O2P +] C13H14O2 + C13H14O2
Wittig-Homer reaction of dimethyl phthalide-3-phosphonates with aldehydes in the presence of lithium bis(trimethylsilyl)amide was investigated. Using their NOE experiments, both the E- and Z-isomers of 3-ylidenephthalides were clearly characterized.

C9H16O2 -> C9H16O2
An unsymmetrically methylated beta-cyclodextrin was prepared and allowed the chiral discrimination of the volatile included compound 1,7 dioxaspiro(5,5) undecane 1.

C7H6O [+ H2] -> C7H8O
An effective recycling system for the reduction of carbonyl compounds to alcohols by 1,5-dehydro-5-deazaflavins, which were produced from 5-deazaflavins and formic acid in a circulatory system, was constructed for the first time, in such a way that the co pound catalyses the reduction, by formic acid, of benzaldehyde. In particular, the reduction using 3,7-dimethyl-10-p-tolyl-5-deazaflavin at 120-degrees-C for 50 h proceeded until the benzaldehyde substrate was exhausted to give 100% yield of benzyl alcoho . The yield based on the catalyst was 3120%, which means 31 recyclings of the catalyst.

C5H8O3 [+ H2] -> C5H10O3
Attempts to introduce new catalytic activities of potential use in synthetic transformations into enzyme active sites are described. Substitution of the naturally occurring zinc in carboxypeptidase A by several metals known to catalyse hydrogenation was i vestigated; a new protein characterised as a rhodium carboxypeptidase was isolated but it failed to show activity as a hydrogenation catalyst for the reduction of a series of dehydroamino acid amides. Horse liver alcohol dehydrogenase was investigated for its potential to act as an oxygen transferase via Lewis acid catalysis. A series of cyclohexenyl and phenylribosides together with new alkenyl(arenyl)oxymethylenoxyethanols was prepared for evaluation as substrates; in the course of this study, novel neig bouring group participation by the oxygen atom of a chloromethyl ether was observed. Although the binding of potential oxygen acceptors (alkenes and aromatic compounds) and oxygen donors (hydrogen peroxide and alkyl hydroperoxides) was demonstrated, oxyge transfer did not occur with the combinations investigated. In contrast to the failure of the above metalloenzymes to catalyse new reactions, papain modified at the active site sulfhydryl group by thiazolium salts and pyridinium salts was shown to exhibit reactions characteristic of the covalently attached cofactor. Thus the thiazolopapains acted as decarboxylation catalysts for pyruvate and the pyridinopapains could be reduced to dihydropyridines which reduced electrophilic carbonyl substrates with small nantiomeric excess.

C7H5BrF2 + C3H8O -> [BrH +] C10H12F2O
Substituted bromomethyl- and chloromethylbenzenes and bis(bromomethyl) benzenes were directly converted, in high yields, to the corresponding methyl- and isopropyl- benzyl ethers by treatment with silver(II) oxide in methanol or isopropanol.

C11H10 [+ C11H6O4] -> C11H8O2 + C11H8O2
Various aromatic hydrocarbons were oxidized with aqueous hydrogen peroxide in the presence of hexafluoroacetone hydrate as catalyst to give para-quinones and/or the ring cleavage oxidation products. The regioselective oxidation of 2-methylnaphthalene to 2 methyl-1,4-naphthoquinone (vitamin K3) was studied in detail.

C7H5NO3 + C4H8O [+ C4H8O] -> C15H21NO5
Catalytic amounts of Yb(fod)3 catalyze a bimolecular ene-like reaction between ordinary aldehydes and vinyl ethers, in which the oxygen functionality is located at the central carbon of an allylic system, These reactions proceed at room temperature in hig yield.

C44H80NO8P -> [C18H30O +] C26H50NO7P
Lipase from Mucor javanicus catalyzed deacylation of phosphatidylcholine(PC) and phosphatidyl ethanolamine(PE) in boric acid-borax buffer regiospecifically to furnish sn-1 lysoPC and sn-1 lysoPE quantitatively.

C9H11Br [+ C9H11Te] -> [Br +] C18H22Te
Bis(phenylethynyl) telluride was found to react readily with 2 equiv of a variety of aryllithium reagents in tetrahydrofuran at -78-degrees-C to afford diaryl tellurides in excellent yields. As judged by Te-125 NMR spectroscopy in tetrahydrofuran at -105- egrees-C, neither a tellurium ate complex nor an unsymmetrical telluride, aryl phenylethynyl telluride, was a detectable intermediate in the reaction. The phenylethynyl group of aryl phenylethynyl tellurides was similarly shown to be substituted by treatm nt with various aryllithiums to afford unsymmetrical diaryl tellurides.

C8H9ClO2S + C4H8O [+ H] -> [Cl +] C12H18O3S
Stannyl radicals Bu3Sn. are generated smoothly and selectively from the distannane BU3Sn-SnBU3, when optimized triplet sensitizers and mild UV irradiation are used. This allows fine tuning of slow consecutive radical steps. For example, carbon-centred rad cals produced by this way can favour slow intramolecular (cyclizations) or , intermolecular additions to double bonds, or dimerization, when no or carefully adjusted H-donors are used. Typical examples am given.

C7H5N + C5H11N -> C12H16N2
Cu(I)Cl promotes the condensation of acetonitrile la and benzonitrile lb with primary and secondary amines 2a-g into amidines 3a-j under mild conditions, in high to quantitative yields. Stoichiometric formation Of Cu(I)-amidines complexes allows to contro the degree of substitution of resulting amidines

C34H40N2O5 + C17H15NO4 -> [C15H12O3 +] C36H43N3O6
9-Fluorenylmethyloxycarbonyl (Fmoc) group can be quickly removed with tetrabutylammonium fluoride hydrate (TBAF.xH2O) in the presence of a large excess of phenylmethanethiol or 1-octanethiol. Subsequent oxidation of the thiol with bis(1-methyl-1H-tetrazol 5-yl) disulfide simultaneously inactivated the TBAF and enabled one-pot peptide bond elongation by the Fmoc strategy.

C7H6O + C4H10Zn -> [C2H4Zn +] C9H12O
(R)-1-Phenylpropan-1-ol has been shown to undergo enantioselective autocatalysis in up to ca. 100% chemical yield and up to 49.2% ee, with retention of configuration, through the addition of diethylzinc to benzaldehyde mediated by a catalytic amount (4-6 ol%) of various amines.

C9H10O2 + C4H11N -> C13H21NO2
Lanthanide(lll) trifluoromethanesulfonates (triflates), such as Yb(OTf)3, Nd(OTf)3 and Gd(OTf)3, catalyze in a extraordinarily efficient way the aminolysis of 1,2-epoxides, affording the corresponding beta-amino alcohols, at room temperature and in a non- rotic solvent (CH2Cl2 or toluene), in very good yields. The reactions are completely anti stereoselective and highly regioselective.

C10H8F6NO4P + C3H8O -> [H2O +] C6H9F6O4P + C7H5N
Reactions of 2,2,2-trihaloethyl or 1,1,1,3,3,3-hexafluoro-2-propyl benzoylphosphonate anions 7 or 10 with hydroxylamine gave the corresponding (alpha-hydroxyiminobenzyl)phosphonates, 3 or 11, respectively, as predominantly (E)-isomers. Refluxing (E)-3a or (E)-3b in EtOH or 2-PrOH caused them to fragment to benzonitrile and mixed phosphodiesters: ethyl trihaloethyl phosphate (12) or 2-propyl trihaloethyl phosphate (13), respectively. (E)-3a did not undergo any fragmentation in boiling water or MeOH. Refluxi g (E)-3a in aprotic solvents led to the formation of benzonitrile and P,P'-bis(2,2,2-trifluoroethyl)pyrophosphate (4a). The rate of fragmentation increased with solvent polarity. Similar behavior was exhibited by 11. The fragmentation of anions 3 and 11 i interpreted in terms of a dissociative mechanism leading to the formation of metaphosphate in the first step. The lack of reactivity in water and methanol is rationalized by assuming stabilization of the starting material by H-bond formation, while the r te enhancement by polar solvent is attributed to stabilization of the transition state and solvation of the departing OH- by the solvent. The metaphosphate formed in the thermal fragmentation of 3a in MeCN was trapped by styrene oxide, as evidenced by the isolation and identification of 2-oxo-2-(2',2',2'-trifluoroethyl)-4-phenyl-1,3,2-dioxaphospholane as a mixture of diastereoisomers 18 and 19.

CO2 -> [O +] CO
The electrocatalytic reduction of CO2 on a carbon/({Ru-0(bpy)(C0)(2)}(n)) (bpy = 2,2'-bipyridine) modified electrode, prepared by electrochemical reduction of (Ru-II(bpy)(CO)(2)Cl-2), leads to the selective and quantitative formation of CO even in pure aq eous electrolyte; the stability of the modified cathode is improved by using a preformed polypyrrolic film functionalized with this complex.

C62H89NO16 [+ C44H73NO13] -> C55H83NO16 + C51H79NO13
Benzyl and methyl esters of rapamycin 42-hemisuccinate were hydrolyzed under very mild conditions to the rapamycin hemisuccinate using lipase from Pseudomonas sp. This selective deprotection was performed on a greater than or equal to 100 mg scale for bot eaters resulting in 50% isolated yield from the methyl ester and 29% from the benzyl ester of the desired acid.

C14H12 [+ CH3FO] -> C15H15FO
Vicinal alkoxy fluorides are efficiently formed by room temperature reaction of phenyl substituted alkenes with commercially available 1-chloromethyl-4-fluoro-1,4-diazobicyclo(2.2.2)octane bis tetrafluoroborate (Selectfluor(TM) F-Teda BF4) in CH3CN in the presence of various alcohols. The reaction follows Markovnikov-type regioselectivity, while stereoselectivity in the case of phenyl substituted benzocyclenes strongly depends on the ring size and the structure of the alcohol.

C3H6 [+ X2] -> C3H6X2
Two general synthetic routes for the preparation of ethylene-bridged ansa-zirconocene dichlorides rac-(1-(eta5-Cp1)-1-R1-2-(eta5-Cp2)-2-R2-C2H2)ZrCl2 (6a-c) bearing different cyclopentadienyl fragments (Cp1,Cp2 = Cp (cyclopentadienyl), Ind (indenyl), Flu fluorenyl)) and a variable bridge substitution pattern (R1, R2= H, Ph) are described, using chiral epoxides as starting materials. Diastereomeric complexes were separated by crystallization. The solid-state structures of two representative examples are re orted. In combination with methylalumoxane (MAO), rac-(1-(eta5-9-fluorenyl)-2-(eta5-1-indenyl)ethane)ZrCl2 (6a), carrying no bulky bridge substituent, and the diastereomeric systems rac-(1-(eta5-9-fluorenyl)-1(R,S)-phenyl-2-(eta5-1(R,S)-indenyl)ethane)ZrC 2 (6b1 = RR,SS; 6b2 = RS,SR), showing different bridge conformations, were used for propene polymerization. The stereoselectivity depends on monomer concentration for all three unsymmetric catalysts. Under comparable conditions 6a and 6b1,2 produce polypr penes with significantly different stereoregularities. This demonstrates the importance of a defined bridge conformation for the design of highly stereoselective catalysts.

C16H14O -> [O +] C16H14
An efficient and general means of reducing anthrones to anthracenes has been developed. The procedure, which uses NaBH4 as the reducing agent in a mixed solvent system of diglyme/methanol, produced anthracenes in essentially quantitative yield from a vari ty of anthrones.

C8H14 [+ O] -> C8H14O
Dioxiranes generated in situ from potassium monoperoxysulfate and cyclohexanones stereoselectively oxidized cyclohexene derivatives to afford epoxides.

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