Sodium Borohydride–Mediated Transesterification

In the presence of sodium borohydride, esters react with alcohols with formation of the corresponding esters. The reaction is sensitive to the solvent, structure of the ester, and is often concurrent with reduction. Thioesters containing an ester group can be selectively cleaved by the reagent. Both esters and thioesters attached to solid support are resistant toward sodium borohydride. The in situ prepared sodium tetraalkoxyborate is introduced as an efficient reagent and catalyst for transesterification.     

Reduction of Aldehydes and Ketones with Potassium Borohydride as Reductant

A series of aldehydes and ketones were reduced by potassium borohydride in an ionic liquid/water ([bmim]PF6/H2O) biphasic system to afford corresponding alcohol with high purity in excellent yields. The ionic liquid/water biphasic system could promote the chemoselectivity and the substituents such as nitro group and chlorine remained intact. Aromatic ketones were not as active as aromatic aldhydes and cyclic ketones owing to their higher steric hindrance. The ionic liquid could be recycled and reused. This protocol has notable advantages of no need of phase transfer catalyst and organic solvents, mild conditions, simple operation, short reaction time, ease work-up, high yields and recycling of the ionic liquid.     

L-Lactide Homopolymerization and Copolymerization with ε-Caprolactone by Tetrahydrosalen Stabilized Yttrium Borohydride Complex

L-lactide（LLA） homopolymerization and copolymerization with ε-caprolactone（CL） in toluene initiated by tetrahydrosalen-supported yttrium borohydride complex were systematically investigated. A possible mechanism of LLA homopolymerization was proposed according to the 1H-NMR result. In addition, PCL-b-PLLA copolymers were synthesized by sequential addition of monomers and their structure was characterized by GPC, 1H-NMR and 13C-NMR.     

Transition Metal–Free Sodium Borohydride Promoted Controlled Hydration of Nitriles to Amides

A transition metal–free process, promoted by sodium borohydride, has been developed for convenient and selective hydration of nitriles to corresponding amides. The present process converts the aromatic, aliphatic, and heteroaromatic nitriles with wide functional group tolerance. The regioselective hydration of one nitrile moiety in the presence of an other nitrile group makes high impact in the present protocol.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]     

Sodium Borohydride – Ammonium Carbonate: An Effective Reducing System for Aldehydes and Ketones

Summary. Reduction of aldehydes and ketones to the corresponding alcohols was achieved in a simple procedure using the system sodium borohydride and ammonium carbonate. This system needs lower excesses of reducing agent and leads to significantly shortened reaction times.     

Simple Reduction of Heteroaromatic Esters to Alcohols Using a Sodium Borohydride–Methanol System

Some heteroaromatic esters were reduced to the corresponding alcohols by using a sodium borohydride–methanol system. The reduction was completed within 0.15–2.0 h in refluxing THF. The alcohol products were isolated after aqueous workup in moderate to excellent yield (48–97%).     

Efficient and Mild Procedure for Reductive Methylation of Amines Using N‐Methylpiperidine Zinc Borohydride

A simple and efficient procedure for reductive methylation of primary and secondary amines using N‐methylpiperidine zinc borohydride (ZBNMPP), giving tertiary amines, is described. The reaction is carried out in methanol at room temperature under neutral conditions.     

Sn-Mediated Catalytic Asymmetric Reduction of Carbonyl Groups by Sodium Borohydride(or Sodium Borodeuteride)

Two remarkable reducing agents NaBH_4 (or NaBD_4)/SnCl_2(orSnCl_4·2Et_2O) with chiral ligands are applied to the asymmetricreduction of carbonyl compounds with excellent chemical yieldsand enantioselective excesses.     

Selective SN2′ Solvolysis in Borohydride Reduction of 2-Isobutylidene-1-indanone/Tetralone

Selective s_N2′ solvolysis in borohydride reduction of the title compounds is described. As a result, an isomer more stable than the normal reduction product is obtained. Confirmative studies have also been carried out to eliminate the probable acid catalysed rearrangement mechanism.     

First One-step Enantioselective Reduction of á-Haloacetophenones into Styrene Oxides using Sodium Borohydride in Water

The synthesis of enantiomerically enriched epoxides especially styrene oxides is an interesting challenge1, since they are often valuable building blocks for various fine chemical 2 products and pharmaceuticals such as β2-, β3-, and α1-adrenergic receptor agonists3, . In recent years, 4 there has been a flood of papers describing the synthetical methods of the chiral non-racemic epoxides5, . Here we firstly developed a green, simple and potential epoxidation system by 6 enantioselecti…     

Facile and Chemoselective Reduction of Carboxylic Acids into Alcohols via Sodium Borohydride Reduction of N‐Acylbenzotriazoles

Carboxylic acids are converted into corresponding alcohols by chemoselective reduction of their benzotriazole amides with sodium borohydride.     

Sn－Mediated Catalytic Asymmetric Reduction of Carbonyl Groups by Sodium Borohydride （or Sodium Borodeuteride）

Two remarkable reducing agents NaBH₄ (or NaBD₄)/SnCl₂(or SnCl₄·2Et₂O) with chiral ligands are applied to the asymmetric reduction of carbonyl compounds with excellent chemical yields and enantioselective excesses.     

Sodium Borohydride–Solid LiClO4: An Effective Reagent for Reducing Aldehydes and Ketones in Aprotic Solvent

An efficient and simple method for the reduction of aldehydes, ketones and acid chlorides has been accomplished by using NaBH₄–solid LiClO₄ in mild conditions at ambient temperature with complete chemoselectivity in reduction of α,β‐unsaturated aldehydes and ketones. The reaction is fast with high yield and simple workup.     

The Unexpected Reductive Products of δ—Alkoxyenal by Sodium Borohydride in Methanol with A Trace of Magnesium Methoxide

Reduction of δ-alkoxy enal 1 and 4 by sodium borohydride in methanol with a catalytic amount of magnesium methoxide gave unexpected methoxylated poducts 3 and 6 respectively.     

Modified Borohydride Agents1a-d Methyltriphenylphosphonium Tetrahydroborate; MePh3P+BH4 − as a Selective and An Efficient Reducing Agent

Abstract

MePh₃P⁺BH₄ ^? is able to reduce aldehydes and ketones to their corresponding alcohols in CH₂Cl₂. Aldehydes are reduced with high selectivity in the presence of ketones. α,β-Unsaturated carbonyl compounds undergo 1,2-reduction and produce their corresponding allylic alcohols in high yields. Carboxylic acid chlorides are also converted to their alcohols with high yields.     

Convenient Method for Reduction of C-N Double Bonds in Oximes,Imines, and Hydrazones Using Sodium Borohydride–Raney Ni System

A practical method has been developed for reduction of C-N double bond in oximes, imines, and hydrazones with sodium borohydride catalyzed by Raney Ni. The reactions were carried out in basic aqueous solution, and the desired products were obtained in moderate yields after a simple procedure. This method can be applied to synthesize simpler aliphatic or aromatic amines and its analogs.     

Borohydride reduction of AgNO<Subscript>3</Subscript> in polyacrylate aqueous solutions: Two-stage synthesis of “blue silver”

Two-stage synthesis of blue silver, complex compound of metal clusters and polyacrylic acid anion having a typical absorption band at 750 nm was performed by the partial oxidation of unstable products resulted from the borohydride reduction of silver cations in polyacrylate aqueous solutions.__________Translated from Kolloidnyi Zhurnal, Vol. 67, No. 2, 2005, pp. 243–247.Original Russian Text Copyright © 2005 by B. Sergeev, Lopatina, Prusov, G. Sergeev.     

Solid-State Hydrogen-Generating Composites Based on Sodium Borohydride: Effect of the Heat Treatment of Boron–Cobalt Catalysts on the Hydrogen Generation Rate

Calcined boron–cobalt catalysts prepared by reduction of cobalt chloride in an aqueous sodium borohydride solution can be successfully used as components of pelletized solid-state hydrogen-generating composites based on sodium borohydride. Morphological changes and phase and chemical transformations occurring in the catalysts with an increase in the calcination temperature were studied. The catalyst performance in hydrolysis of sodium borohydride was determined. The hydrogen generation rate depends on the specific surface area of the calcined sample.     

Reduction of 3‐Acyl Derivatives of Oxindoles,Benzo[b]furan‐2‐ones,and Benzo[b]thiophen‐2‐ones to the Corresponding Alkyl Derivatives by Sodium Borohydride–Acetic Acid

It was found that 3‐acyl derivatives of oxindoles, benzo[b]furan‐2‐ones, and benzo[b]thiophen‐2‐ones could be efficiently and conveniently reduced to the corresponding alkyl derivatives by pelletized sodium borohydride in acetic acid. A typical procedure involves heating the acylated substrates for approximately 90 min in a slurry of glacial acetic acid and sodium borohydride to provide the 3‐alkyl product in yields ranging from 62% to 96%. This synthetic methodology represents a convenient approach to the synthesis of the alkyl derivatives.