 The R @-@ groups on the sulfur , though typically methyls , have been used to synthesize reagents that can perform enantioselective variants of the reaction ( See Variations below ) . The size of the groups can also influence diastereoselectivity in alicyclic substrates . 
 The R @-@ groups on the sulfur , though typically methyls , <a href='been_done' title='1'><mark>have</mark></a> been used to synthesize reagents <a href='null_relcl' title='2'><mark>that</mark></a>can perform enantioselective variants of the reaction ( See Variations below ) . The size of the groups can also influence diastereoselectivity in alicyclic substrates . 
Da R @-@ groups on tdasulfur , though typically methyls , done been used to synthesize reagents can perform enantioselective variants of the reaction ( See Variations below ) . The size of the groups can also influence diastereoselectivity in alicyclic substrates .