85 research outputs found
Applications of liver acetone powders in enantioselective synthesis
Applications of liver acetone powders (crude enzymes) as possible substitutes for purified enzyme preparations, hydrolases, in enantioselective organic transformations have been systematically investigated. (1R, 2R)-2-(4-Alkylphenoxy)cyclohexan-1-ols, (1R, 2R)- & (1S, 2S)- 2-nitroxycyclohexan-1-ols, (1R, 2S)-2-arylcyclohexan-1-ols, (3R, 4R)-6-methyl-3-phenylhept-1- en-4-ol, and (R)-1-(naphth-1-yl)ethanol have been synthesized in enantiomerically pure form via the enantioselective hydrolysis of the corresponding racemic acetates mediated by liver acetone powders
A novel, tandem construction of C-N and C-C bonds: facile and one-pot transformation of the Baylis-Hillman adducts into 2-benzazepines
A novel reaction involving tandem construction of C-N and C- C bonds via the simultaneous Ritter and Houben-Hoesch reactions on Baylis-Hillman adducts leading to a convenient, one-pot synthesis of 2-benzazepine derivatives is described. A facile stereoselective transformation of the Baylis-Hillman adducts into (E)- and (Z)-allyl amides is also presented
Novel titanium(IV) chloride catalyzed olefination of aldehydes: a simple and convenient synthesis of trans-cinnamic acids
A variety of aromatic aldehydes were stereoselectively transformed into (E)-cinnamic acids via the reaction with ethyl bromoacetate and triphenylphosphine in the presence of catalytic amount of titanium tetrachloride, followed by hydrolysis and crystallization
First example of electrophile induced Baylis-Hillman reaction: a novel facile one-pot synthesis of indolizine derivatives
Treatment of pyridine-2-carboxaldehyde with activated alkenes such as alkyl vinyl ketones and cyclic enones in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) provides a novel facile one-pot synthesis of indolizine derivatives, thus for the first time describing an electrophile induced Baylis-Hillman reaction
Enantioselective hydrolysis of 2, 2-disubstituted oxiranes mediated by microsomal epoxide hydrolase
2-Aryl-2-methyloxiranes are enantioselectively hydrolyzed with microsomal epoxide hydrolase from pig liver to provide 1, 2-diols containing a tertiary benzylic alcohol stereogenic centre upto 34% enantio-meric purities
Enantioselective synthesis using crude enzymes
Chiral trans-2-aryloxycyclohexan-l-ols, trans-2-alkoxy cyclohexan-1-ols, trans-2-arylcyclohexan-l-ols, homoallyl alcohols, 1-aryl-1-alkanols, 1,2-diphenylethane-l,2-diol are prepared in high optical purities via enantioselective hydrolysis of acetates of the corresponding racemic alcohols using crude enzymes such as pig liver acetone powder (PLAP), goat liver acetone powder (GLAP), chicken liver acetone powder (CLAP) and bovine liver acetone powder (BLAP)
A new protocol for the syntheses of (E)-3-benzylidenechroman-4-ones: a simple synthesis of the methyl ether of bonducellin
Development of a simple new methodology for the synthesis of (E)-3-benzylidenechroman-4-ones using methyl 3-aryl- 3-hydroxy-2-methylenepropanoates, the Baylis-Hillman adducts derived from methyl acrylate, and the application of this methodology for the synthesis of the methyl ether of bonducellin, an important natural product, and 3-(4-methoxybenzylidene)- 6-methoxychroman-4-one, an antifungal agent, are described
Towards chiral diamines as chiral catalytic precursors for the borane-mediated enantioselective reduction of prochiral ketones
Two chiral diamines (3S)-3-anilinomethyl-1,2,3,4-tetrahydroisoquinoline (1) and (2R)-2-anilinomethylpiperidine (2) have been employed as chiral catalytic sources in the borane-mediated asymmetric reduction of prochiral ketones thus providing the resulting secondary alcohols in good enantiomeric purities (up to 81% ee)
Tandem construction of carbon-carbon and carbon-oxygen bonds in the Baylis-Hillman chemistry: synthesis of functionalized dl-bis-allyl ethers
Tandem coupling between acrylonitrile and aryl aldehydes under the catalytic influence of DABCO involving the construction of two carbon-carbon bonds and one carbon-oxygen bond leading to the synthesis of dl-functionalized bis-allyl ethers has been described
Methanolic trimethylamine mediated Baylis-Hillman reaction
Application of methanolic trimethylamine, the tertiary amine containing minimum number of carbon atoms with lowest possible molecular weight, for mediating the Baylis-Hillman coupling of various aldehydes with activated olefins viz. methyl acrylate, acrylonitrile and acrolein is described
- …