Is stereochemistry destroyed by #S_(N)1# reactions...?

1 Answer
Apr 5, 2017

My word it is...........

Explanation:

#S_(N)1# reactions are PRESUMED to occur thru the intermediacy of a carbocation, i.e. it is a dissociative reaction:

#X-CR_1R_2R_3 rarr underbrace(""^(+)CR_1R_2R_3)_"carbocation intermediate" + X^-#

The carbocation intermediate is three coordinate, and thus the ipso carbon CANNOT support stereoisomerism. The subsequent bond making reaction would give rise to a racemic mix of enantiomers.