electrophilic reactivity of arenes coordinated to the chromium tricarbonyl unit has been developed into several distinct methods for coupling carbon nucleophiles with aromatic rings. Addition of the nucleophile produces stable η5-cyclohexadienyl chromium complexes which can be oxidized to induce loss of the endo hydrogen and the metal, overall nucleophilic substitution for hydrogen. Alternatively, the intermediate
SEMMELHACK M. F.; HARRISON J. J.; THEBTARANONTH Y., J. ORG. CHEM., 1979, 44, NO 18, 3275-3277
作者:SEMMELHACK M. F.、 HARRISON J. J.、 THEBTARANONTH Y.
DOI:——
日期:——
Asymmetric Conversion of Arenechromium Complexes to Functionalized Cyclohexenones: Progress toward Defining an Optimum Chiral Auxiliary
作者:Anthony J. Pearson、Alexander V. Gontcharov
DOI:10.1021/jo971676o
日期:1998.1.1
the asymmetric synthesis of 5-substituted cyclohexenones via nucleophileaddition to (alkoxyarene)chromium tricarbonyl complexes is described. Diastereoselectivity during the nucleophileaddition step was achieved using alkoxy substituents derived from terpenoid substrates as chiralauxiliaries. Selectivities as high as 24:1 were obtained when 2-phenylisoborneol was used as the chiralauxiliary and
Studies on asymmetric conversion of arenes to functionalized cyclohexenones via chiral auxiliary-promoted nucleophilic additions to arene-chromium complexes
作者:Anthony J. Pearson、Alexander V. Gontcharov、Paul D. Woodgate
DOI:10.1016/0040-4039(96)00367-x
日期:1996.4
Reactions of alkoxyarene-chromium tricarbonyl complexes, having chiral alkoxy groups, with isobutyronitrile anion, followed by standard work-up produces substituted alkoxycyclohexadienes with diastereomeric excesses of up to 76%. Conversion to cyclohexenones allows recovery of the chiral alcohol auxiliary. The absolute stereochemistry of the product from the optimum procedure was determined by using