Synthesis of acyl(phenylselanyl)methylidene(triphenyl)-λ<sup>5</sup>-arsanes and their Wittig-type reactions
作者:Zhi-Zhen Huang、Xian Huang、Yao-Zeng Huang
DOI:10.1039/p19950000095
日期:——
Acyl(phenylselanyl)methylidene(triphenyl)-lambda(5)-arsanes 3 have been synthesized by treating acylmethylidene(triphenyl)-lambda(5)-arsanes 1 with phenylselanyl iodide 2; alpha-selanylarsonium ylides 3 are sufficiently reactive to undergo Wittig-type reactions, affording a novel method for the stereoselective synthesis of (Z)-alpha-phenylselanyl alpha,beta-unsaturated ketones 6.
Cross-aldol reaction between benzaldehyde and β-phenylselanyl enoxysilanes derived from phenylselanylmethylketones
The BF3-mediated aldol reaction between benzaldehyde and beta-phenylselanyl enoxysilanes 1 derived from alpha-phenylselanylmethylketones has led to syn aldols 2 and alpha,alpha-bis(phenylselanyl) ketones 3 as by-products. Using tetrabutylammonium fluoride, the syn and anti aldols 2a were formed from 1a. Syn, syn-2-phenylselanyl 1,3-diols 5a and 5d were obtained by borane reduction of aldols 2a and 2d respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.
New synthesis and cyclopropanation of α-phenylselanyl α,β-unsaturated ketones with non-stabilized phosphorus ylides
A general method for the preparation of α-phenylselanyl enones is described. Phosphorus ylides react with these α-phenylselanyl enones in a 1,4-addition, leading to cyclopropanes and/or dihydrofurans, depending on the substitution pattern. This unusual reactivity is due to the phenylselanyl moiety, hindering the carbonyl of the enone and making it less prone to 1,2-additions or promoting conjugate