The addition of dialkylzincs or diphenylzinc to substituted phenylacetylenes in the presence of catalytic amounts of Ni(acac)(2) in THF : NMP mixtures produces syn-carbozincation products with good to excellent regio-and stereoselectivity. After quenching with an electrophile (iodine, acyl chloride, allyl bromide) tetrasubstituted olefines are obtained in good to satisfactory yields. An intramolecular version of the reaction is possible using a terminal triple bond bearing an iodine at a remote position. More substituted iodo-alkynes furnish only reductive elimination products. An application to a stereoselective synthesis of (Z)-tamoxifen (Z: E > 99: 1) has been developed. (C) 1998 Elsevier Science Ltd. All rights reserved.
Studemann; Knochel, Angewandte Chemie - International Edition in English, 1997, vol. 36, # 1-2, p. 93 - 95
作者:Studemann、Knochel
DOI:——
日期:——
Nucleophilic addition to coordinated polyenes: a novel method for the liberation of the trimethylenemethane ligand involving CC bond formation
作者:William A. Donaldson、M.Azad Hossain
DOI:10.1016/s0040-4039(00)74664-8
日期:1992.7
Reaction of (trimethylenemethane)Fe(CO)3 with carbon nucleophiles, followed by protonation yields the corresponding methallylated nucleophile in good yield. Products which incorporate carbonyl ligands are also observed.