Transition-metal-catalyzed decomposition of diazo(trialkylsilyl)-acetates: Intermolecular formation and trapping of carbonyl ylides
作者:Mechthild Alt、Gerhard Maas
DOI:10.1016/s0040-4020(01)90472-7
日期:——
crotonaldehyde, or acetaldehyde generates carbonylylides which can be trapped with dimethyl fumarate. dimethyl maleate, and dimethyl acetylenedicarboxylate to give tetrahydrofurans 4,6,7, and 8 and dihydrofuran 10, respectively. Decomposition of 2a in the presence of benzaldehyde and methyl cyanoformate affords no products derived from a carbonylylide, but rather the oxazole 12. X-ray crystal structures
Regitz, M.; Weise, G.; Lenz, B., Bulletin des Societes Chimiques Belges, 1985, vol. 94, # 7, p. 499 - 520
作者:Regitz, M.、Weise, G.、Lenz, B.、Foerster, U.、Urgast, K.、Maas, G.
DOI:——
日期:——
Untersuchungen an diazoverbindungen und aziden
作者:Thomas Allspach、Helmut Gümbel、Manfred Regitz
DOI:10.1016/0022-328x(85)80146-7
日期:1985.7
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.
Polymeric dicarbonyl ruthenium(I) acetate - An efficient catalyst for alkene cyclopropanation with diazoacetates
The polymeric complex [Ru2(CO)4(mu-OAc)2]n is the first Ru(I) catalyst that efficiently catalyzes cyclopropanation of alkenes with diazoacetic esters. The related dinuclear catalyst Ru2(CO)4(mu-OAc)2(MeCN)2 shows a similar performance only for cyclopropanation of monosubstituted alkenes.