Oct 16, 2011· The reduction of a carboxylic acid by borane TS1 in this scheme is modified from before to include an extra borane coordinating to the oxygen of the O-R group. I will include here the intrinsic reaction coordinate [computed at ωB97XD/6-311G(d,p)], since it …
Form Supplied in: neat complex, colorless liquid, ca. 10 M in BH 3; contains slight excess of dimethyl sulfide. Analysis of Reagent Purity: active hydride is determined by hydrolysis of an aliquot in glycerol–water–methanol mixture and measuring the hydrogen evolved according to a standard procedure. 3 a 11 B NMR (CH 2 Cl 2 ) δ −20.1 ppm .
Tris(pentafluorophenyl)boron B(C 6 F 5) 3 is an effective catalyst for the reduction of tertiary and N-phenyl secondary amides in the presence of a silane. Various amides can be reduced in near quantitative yield, with minimal purification, at low temperatures, and with short reaction times.
A Solution of Borane in Tetrahydrofuran. A Stereoselective Reducing Agent for Reduction of Cyclic Ketones to Thermodynamically More Stable Alcohols. The Journal of Organic Chemistry 2001, 66 (22), 7514-7515. DOI: 10.1021/jo010401c. Md. T. Hossain and, Jack W. Timberlake.
Borane- dimethyl sulfide is used for hydroboration and reduction reactions. It is used in the reduction of aldehydes, ketones, epoxides and carboxylic acids to give corresponding alcohols. It is also involved in the Corey-Itsuno reduction. It acts as an intermediate in the preparation of …
Boranes (Dimethylsulfide Borane, Borane-Tetrahydrofuran Complex) The most interesting application is as a borane source for oxazeborolidine catalyzed asymmetric reductions of ketones ( Corey-Bakshi-Shibata Reduction ). Very interesting is also the direct reduction of carboxylic acids to alcohols (BMS) and amides to amines (BTHF).
Reductions. Reductions of aldehydes, ketones, epoxides, esters, and carboxylic acids give the corresponding alcohols. Lactones are reduced to diols, and nitriles are reduced to amines. Acid chlorides and nitro groups are not reduced by BMS. Borane dimethylsulfide is one of the most common bulk reducing agents used in the Corey–Itsuno reduction.
Michler's ketone is reduced to 4,4′-bis(dimethylamino)diphenyhnethane. The acid probably facilitates the amide reduction by protonating the carbonyl oxygen.
Once the complex is established, hydride is delivered until the carbonyl is reduced to the hydroxyl or the borane has no more hydrides to deliver. The final products, after workup with water, are the corresponding alcohol and boric acid. Carboxylic acids and carbon nitrogen double and triple bonds are susceptible to reduction with borane.
Borane reductions don't work well with electron deficient carbonyl groups. Why is that so, and how isn't the carboxyl group an electron deficient group? organic-chemistry reaction-mechanism