Isomerization of and chloride migration in representative complexed 1‐chloro‐2‐methyl‐1‐propenylmetals

A computational study of the title compounds, in which the metal functionality is lithium or dimethylboryl, each complexed with NH3, compares effects of complexation upon the title compounds with ammonia against those experimentally observed with TMEDA. Previous similar calculations predicted intermediates formed with loss of stereospecificity but did not consider complexation effects, which were reported to increase the yield of the stereospecific reactions. In contrast, when ammonia is included to model complexation by TMEDA, an ionized form of the title compounds is generally favored that is capable of maintaining stereochemistry. This form is a Met‐Cl associated intermediate, in which Cl−has migrated from carbon to become associated with Met. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9: 623–630, 1998