Reducing properties of 1,2-diaryl-1,2-disodiumethanes
摘要:
1,2-Diphenyl- and 1-phenyl-2-(2-pyridyl)-1,2-disodiumethane efficiently dehalogenate vic-dibromoderivatives, affording the corresponding alkenes. The reaction proceeds rapidly, under mild conditions and is tolerant of a variety of functional groups (alcohol, carboxylic acid, ester and amide). This procedure was successfully extended to similar vic-disubstituted compounds. (c) 2005 Elsevier Ltd. All rights reserved.
New stereospecific syntheses of pheromone bombykol and its three geometrical isomers
作者:Norio Miyaura、Hiroshi Suginome、Akira Suzuki
DOI:10.1016/s0040-4039(00)81700-1
日期:——
We describe stereospecific syntheses of pheromone, bombykol and the threegeometricalisomers by means of the palladium-catalyzed cross-coupling between an appropriate alkenylborane and an alkenyl halide in the presence of a base.
THF gives the corresponding amines in 70–76% yields. Reduction of nitriles yields the corresponding amines in 70–75% yields. The I2/NaBH4 system is useful in the hydrocarboration of olefins and the corresponding alcohols are obtained in 78–92% yields after H2O2/OH− oxidation. The reagent system is also useful for the reduction of carboxylicesters and acids to the corresponding alcohols in 60–90% yields
Although molecular bromine (Br2) is a useful brominating reagent, it is not easy to handle. Herein, we describe the preparation of a novel air-stable bromine complex prepared from 1,3-dimethyl-2-imidazolidinone (DMI) and Br2, which was identified to be (DMI)2HBr3 by spectral and X-ray techniques. This complex was then used to brominate olefins, carbonyl compounds, and aromatics, as well as in the Hofmann
We investigated the reductive elimination of several functionalized and non-functionalized vic-dibromides with 1,2-diphenyl-, 1, 1,2,2-tetraphenyl- and l-phenyl-2-(2-pyridyl)-1,2-disodioethane. The reaction, involving some of the less expensive organic and inorganic reagents, proceeds under mild conditions, and is tolerant of a variety of functional groups. Extension of this procedure to similar 1,2-disubstituted compounds was also investigated. Reductive eliminations run on stereochernical probe compounds strongly suggest that this reaction proceeds via a "single electron" reductive elimination reaction pathway. (c) 2007 Elsevier B.V. All rights reserved.
Efficient utilization of tetrabutylammonium bifluoride in halofluorination reactions