Reaction of nucleophiles with alkoxycarbene complexes of chromium: a general access to polycyclic substituted butenolides
摘要:
A series of new substituted butenolides has been obtained either by reacting alkynylalkoxycarbene complexes 3 with simple nucleophiles such as metal hydrides, metal alkoxides and metal alkyls, or by reacting simple alkoxycarbene complexes 6 with more elaborate nucleophiles such as metal alkynolates or metal alkynyls. (C) 2002 Elsevier Science Ltd. All rights reserved.
A Major Breakthrough in the Use of Alkoxycarbene Complexes of Chromium and Tungsten for the Synthesis of Elaborate Organic Compounds: Dihydropyridine Induced Reductions and Cascade Insertion Reactions
Alkoxy (alkyl)carbene complexes of tungsten and chromium react with dihydropyridine and N-methyldihydropyridine to give respectively pyridinium ylid complexes and N-methylpyridinium tungstates and chromates. These two types of complexes can be used, for the former, as cyclopropanation reagents, for the latter, as unprecedented initiators of cascade multiinsertions of olefins, alkynes and CO. These
Chromium alkoxycarbene complexes tethered to a triple bond react with a series of chiral dihydropyridines, among which is N-methyl-1,2-dihydronicotine, to give enantioselectively, upon cascade insertion reactions, polycyclic butenolides. (C) 2001 Elsevier Science Ltd. Air rights reserved.
Reaction of nucleophiles with alkoxycarbene complexes of chromium: a general access to polycyclic substituted butenolides
A series of new substituted butenolides has been obtained either by reacting alkynylalkoxycarbene complexes 3 with simple nucleophiles such as metal hydrides, metal alkoxides and metal alkyls, or by reacting simple alkoxycarbene complexes 6 with more elaborate nucleophiles such as metal alkynolates or metal alkynyls. (C) 2002 Elsevier Science Ltd. All rights reserved.