Synthesis of 3-aryl-3-trimethylsilylcyclopropenes and their dibenzoyl derivatives. Possible cyclopropenyl anion precursors? †
摘要:
3-Ary-1-3-trimethylsilylcyclopropenes (1) were synthesized by a four-step reaction sequence starting from known benzoyl trimethylsilanes. These cyclopropenes were thermalized on a gas chromatography column and the products were collected and identified. Their 1,2-dibenzoyl derivatives (2) were prepared in a two-step transformation beginning with 3-aryl-1,2,3-tris(trimethylsilyl)cyclopropenes (5), the ultimate intermediates in the syntheses of 1. These compounds (2) are rare examples of isolable cyclopropenes with electron withdrawing groups at the vinyl positions. Fluoride-induced desilylation reactions of electron deficient cyclopropenes also are described and a carbon-centered electrophile has been successfully used to trap a putative cyclopropenyl anion.
Synthesis of 3-aryl-3-trimethylsilylcyclopropenes and their dibenzoyl derivatives. Possible cyclopropenyl anion precursors? †
作者:Sangdon Han、Steven R. Kass
DOI:10.1039/a900376b
日期:——
3-Ary-1-3-trimethylsilylcyclopropenes (1) were synthesized by a four-step reaction sequence starting from known benzoyl trimethylsilanes. These cyclopropenes were thermalized on a gas chromatography column and the products were collected and identified. Their 1,2-dibenzoyl derivatives (2) were prepared in a two-step transformation beginning with 3-aryl-1,2,3-tris(trimethylsilyl)cyclopropenes (5), the ultimate intermediates in the syntheses of 1. These compounds (2) are rare examples of isolable cyclopropenes with electron withdrawing groups at the vinyl positions. Fluoride-induced desilylation reactions of electron deficient cyclopropenes also are described and a carbon-centered electrophile has been successfully used to trap a putative cyclopropenyl anion.
Formation of Transient and Long-Lived Cyclopropenyl Anions
作者:Tina L. Arrowood、Steven R. Kass
DOI:10.1021/ja991224o
日期:1999.8.1
yclopropene in the gas phase (eq 1).15 In this work we provide condensed-phase mechanistic evidence that the fluoride-induced desilylation of a 3-trimethylsilylcyclopropene derivative leads to a transient cyclopropenyl anion intermediate. The first preparation of a long-lived cyclopropenyl anion in solution and its corresponding UV-visible spectrum also are presented.