Sequential radical cyclization, alkoxy-radical fragmentation, and recyclization processes: a novel method for the synthesis of fused cycloheptanones and cyclooctenones from cyclohexanones
Preparation de composes bicycliques et d'heterocyclesazote ou oxygene bicycliques possedant une fonction cetone, enone ou alcool, a partir de cetones acetyleniques
制备 de composes bicycliques et d'heterocycles azote ouoxye bicycliques possedant une fonction cetone, enone ou alcool, a partir de cetones acetyleniques
Construction of Methylenecycloheptane Frameworks through 7<i>-Exo-Dig</i> Cyclization of Acetylenic Silyl Enol Ethers Catalyzed by Triethynylphosphine−Gold Complex
作者:Hideto Ito、Hirohisa Ohmiya、Masaya Sawamura
DOI:10.1021/ol101860j
日期:2010.10.1
A cationic gold(I) complex bearing a semihollow-shaped triethynylphosphine ligand efficiently catalyzed the 7-exo-dig cyclization of silylenolethers with an ω-alkynic substituent. The reaction gave various methylenecycloheptane derivatives with an exo- or endocyclic carbonyl group. The protocol was applicable not only to cyclic substrates that form bicyclic frameworks but also to acyclic ones with
tethered with a vinyl azide group undergo a Schmidt-hydrolysis sequence to give secondary lactams bearing a ketone side chain. Secondary lactams are obtained in a regioselective manner that is not possible in a conventional Schimdt reaction. In addition to the well-documented C-2 nucleophilicity, the N nucleophilicity of vinyl azide disclosed in this work opens a new direction for reaction invention involving
Gold-catalysed room-temperature cycloisomerisation of alkynes and unactivated enolisable ketones
作者:Paul W. Davies、Christelle Detty-Mambo
DOI:10.1039/c003473h
日期:——
The cycloisomerisation of simple keto-alkynes proceeds at room temperature under the mild conditions of gold catalysis. Bicyclic fused and spiro compounds can be obtained by overall 5-exo and 6-exo carbon–carbon bond-forming cyclisations.