A simple, rapid, and eco-friendly method for NaBH4 reduction of carboxylic acids to alcohols under solvent-free conditions was developed using a combination of 2,4,6-trichloro-1,3,5-triazine (TCT) with a catalytic amount of triphenylphosphine as an acid activator. With the 1:0.2:1.5:2 ...
In the presence of a tertiary amine, sodium borohydride (NaBH4) combined with zinc chloride (ZnCl2) showed powerful reducing properties and carboxylic esters were smoothly reduced to their corresponding alcohols which were not obtained by reduction with NaBH4 and ZnCl2 alone. Tetrahydrofuran (THF) was...
of reduction because each process adds two new C—H bonds to the starting material. Introduction 2 Oxidation and Reduction • There are three types of reductions differing in how H 2 is added. • The simplest reducing agent is molecular H 2 . Reductions using H 2 are carried out with ...
Slightlyacidic.1to1.5equivalentsofPCC Pyridiniumdichromate(PDC)lessacidicthanPCC.InDMF,easilygetcarboxylicacid Swernoxidation Proceedsrapidlyatlowtemprature.Canbeemployedforthepreparationof-ketoneandacylsilaneswhicharepronetohydration,polymerization,andairoxidation.SwernoxidationcanbeperformedwithDMSO,P2O5,andEt3N...
FUJII H.A practical and stereoselective reduction of 3-keto2-methyl esters or 3-keto-2-methyl amides into erythro-3-hydroxy-2-methyl esters or mrythro-3-hydroxy-2-methyl amides with NaBH4 catalyzed by MnCl2.Tetrahedron Letters.1991.6147-6150...
Complex 3 catalyzes asymmetric NaBH4 reduction of C(3)-disubstituted acrylates in the presence of 0.05–1 mol% of 3 in a 1:1 CH3OHCH2Cl2 mixed solvent at 0 °C−25 °C to quantitatively yield the corresponding saturated prenyl-type motif with an enantiomer ratio (er) of up to...
3-Addhydride(H–)andaproton(H+)e.g.NaBH4andLiAlH4.ThesereagentsdeliverH–toasubstrate,andthenaprotonisaddedfromH2Ooranalcohol.http://www.tutorhomework.com/Chemistry_Help/electronegativity_table/electronegativity.html ReductionofAlkenes AdditionofH2occursonlyinthepresenceofametalcatalyst(catalytichydrogenation)...
Hummel, 1999, “Large-scale applications of NAD(P)-dependent oxidoreductases: recent developments,” Trends Biotechnol. 17(12):487-492. Jiang et al., 2000, “Highly enantioselective reduction of achiral ketones with NaBH4/Me3SiCl catalyzed by (S)-α,α-diphenylpyrrolidinemethanol,” Tetrahedron...
NaBH4 1. Carboxylic acid was reduced to the corresponding alcohol using NaBH_4/I_2 System in dioxane with good selectivity and yields,their yields are 90%～99%. 以二氧六环为溶剂,在NaBH4/I2体系中,高产率、高选择性地还原羧酸得到相应的醇,产率达到90%~99%。 2. We have studied the factors ...
8.05.6.2 Chiral Hydrides Hydride reductions of CQN groups are well known in organic chemistry and it was therefore obvious to try to use chiral auxiliaries in order to render the reducing agent enantioselective.172 Several chiral reducing agents starting from BH3, LiAlH4, or NaBH4 and relatively...