PARA PRODUCTS FROM META-ARYLCADMIUM REAGENTS - CINE SUBSTITUTION

The apparent rearrangement of m-anisylcadmium reagent (1a) has been studied for the purpose of elucidating the scope and mechanism of this unusual behavior. Trapping experiments have been carried out with acetyl chloride, acetyl bromide, acetic anhydride, diacetyl sulfide, phenyl cyanate, and bromine, the products being analyzed by GLC and confirmed by IR and NMR spectroscopy. The extent of formation of the para isomer is the same for the two acid halides and bromine and considerably less for acetic anhydride and phenyl cyanate. With diacetyl sulfide there is no para isomer observed. Experiments with other substituted arylcadmium reagents support the view that this behavior depends on the electron-donor capability of the substituent. Thus, reagents substituted at the meta position with CH3, CF3, and F afforded only meta products with acetyl chloride, while the CH3S substituent afforded some para isomer. Deuterium labeling and trapping experiments have been used to gain information about intermediates in this cine substitution. © 1979, American Chemical Society. All rights reserved.