Arene Chromium Tricarbonyl Stabilised Benzylic Carbocations
1993; Thieme Medical Publishers (Germany); Volume: 1993; Issue: 05 Linguagem: Inglês
10.1055/s-1993-22443
ISSN1437-2096
AutoresStephen G. Davies, Timothy J. Donohoe,
Tópico(s)Synthesis and Biological Activity
ResumoThe ability of the chromium tricarbonyl unit to stabilise benzylic carbocations and oxonium ions is described. We have investigated the use of arene chromium tricarbonyl complexes as chiral auxiliaries for asymmetric synthesis. The synthesis of homochiral tetrahydroisoquinolines, tetrahydrobenzazepines, and 2-aryltetrahydropyrans via intramolecular cyclisation of a nucleophile onto chromium tricarbonyl stabilised benzylic carbocations and oxonium ions is described. 1. Introduction 2. Evidence for the Chromium Tricarbonyl Stabilisation of Benzylic Carbocations 3. Acyclic Systems without ortho Substitution 3.1 Carbocations 3.2 Oxonium Ions 4. Bicyclic Complexes 4.1 (6-5) Ring Systems 4.2 (6-6) Ring Systems 5. ortho Substituted Acyclic Compounds 5.1 Carbocations 5.2 Oxonium Ions 6. Miscellaneous Applications of Chromium Tricarbonyl Stabilised Carbocations
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