Cascade Reactions of β-Amino-Substituted α,β-Unsaturated Fischer Carbene Complexes with 1,5-Dien-3-ynes as a Convenient Access to Ring-Annelated Benzene Derivatives
作者:Yao-Ting Wu、Mathias Noltemeyer、Armin de Meijere
DOI:10.1002/ejoc.200500130
日期:2005.7
achieve good chemical yields. This new cascade reaction of Fischer carbene complexes provides a direct route to trindanone analogues under milder conditions than traditional methods, and is compatible with more functionalities. Compounds 14 and 15 with steroid-like skeletons were thus prepared in 54–77 % yields (4 examples) from complex 1-iPr and the bicyclic alkyne 2. Hexacycles 17 and 18 were accessible
The outcome of the photocycloaddition of cyclohex-2-enones to 2-alkylprop-2-enenitriles differs basically from that of the corresponding 2-alkylbut-1-en-3-ynes. While the latter afford mainly products resulting from 1,6-cyclization of the intermediate triplet alkyl-(prop-2-ynyl) 1,4-biradical, the former give only cyclobutane-carbonitriles resulting from 1,4-cyclization of the singlet alkyl-cyanoalkyl 1,4-biradical.
Apparu,M.; Glenat,R., Bulletin de la Societe Chimique de France, 1968, p. 1106 - 1112