Nung Min Yoon

An excellent nickel boride catalyst for the cis-selective semihydrogenation of acetylenes

Abstract Internal alkynes were hydrogenated quantitatively to the corresponding cis -alkenes over nickel boride (Ni 2 B), prepared on borohydride exchange resin (BER) in methanol under hydrogen atmosphere. Further hydrogenation was very slow under the reaction conditions, and pure cis -alkenes were conveniently isolated in excellent yields. Hydroxy and ester functional groups did not interfere with the semihydrogenation.

BOROHYDRIDE EXCHANGE RESIN, A NEW REDUCING AGENT FOR REDUCTIVE AMINATION

Abstract Borohydride Exchange Resin is a useful, convenient reducing agent for the reductive amination of aldehydes and ketones in alcoholic solvent.

Chemoselective reduction of carbonyl compounds with borohydride exchange resin in alcoholic solvents

Abstract Borohydride exchange resin exhibited a high chemoselectivity not only between aldehyde and ketone but also between aldehydes and between ketones.

Reduction of Azides to Amines with Borohydride Exchange Resin – Nickel Acetate

Abstract Borohydride exchange resin (BER) - nickel acetate system in methanol readily reduces both aliphatic and aromatic azides to the corresponding amines in excellent yields.

THE SEMIHYDROGENATION OF ACETYLENES OVER PD CATALYST ON BER IN THE PRESENCE OF CSI

Abstract In the presence of CsI, Pd catalyst on borohydride exchange resin (BER) in 95% ethanol exhibits a perfect selectivity for the semihydrogenation of acetylenes, providing the corresponding terminal olefins or cis -olefins quantitatively at room temperature.

Synthesis of Thiols via Palladium Catalyzed Methanolysis of Thioacetates with Borohydride Exchange Resin

Abstract Various thiols are prepared quantitatively from the corresponding thioacetates via Pd catalyzed methanolysis with borohydride exchange resin under a mild and neutral conditions. One-pot synthesis of thiols from alkyl halides through the formation of alkyl thioacetates using thioacetate exchange resin followed by methanolysis is also described.

Selective Reduction of α,β-Unsaturated Ketones with Potassium Triphenylborohydride

Abstract Potassium triphenylborohydride is an excellent 1,4-reducing agent for acyclic enones and β-substituted cyclohexenones, and shows a greater tendency for 1,4-reduction than K-Selectride for β-substituted cyclohexenones and aromatic enones.

A new coupling reaction of alkyl iodides with α,β-unsaturated esters using Ni2B(cat.)-BER in methanol

Alkyl iodides can be coupled with α,β-unsaturated esters using Ni2B(0.05–0.2 eq)-BER(3 eq) in methanol at room temperature. Products (68–95%) are conveniently isolated, simply filtering the resin and evaporating the excess enoates and methanol.

Selective Reduction Among Carboxylic Acids with Sodium Borohydride

Abstract The selective reduction among carboxylic acids via acyloxyborohydrides derived from sodium borohydride and carboxylic acid mixture is demonstrated.

Rapid reduction of carboxylic acid salts with borane in tetrahydrofuran.

Abstract Carboxylic acid salts are rapidly reduced to the corresponding alcohols with two molar equivalents of borane in THF. A possible mechanism via acyloxyborane is presented.