Solvolysis of N,N-dimethylthiocarbamoyl chloride: effect of sulfur-for-oxygen substitution upon kinetics and product partitioning

A study of the solvolyses of N,N-dimethylcarbamoyl chloride (1) was extende d to the solvolyses of N,N-dimethylthiocarbamoyl chloride (2). The specific rates of solvolysis of 2 at 0.0 degrees C are two to three orders of magni tude greater than those for 1. Analysis of the data using the extended Grun wald-Winstein equation leads to sensitivities l and m and an l/m ratio whic h are lower for 2 than those previously reported fur 1. product selectiviti es in mixtures of water with ethanol or methanol indicate a greater prefere nce for reaction with alcohol for 2. All observations can be rationalized i n terms of the formation of a more stable carbocation from 2. leading to an earlier transition state, reduced nucleophilic solvation and the possibili ty of extensive progression to a free carbocation prior to product formatio n. Copyright (C) 2000 John Wiley & Sons, Ltd.