Table 1.

Enantioselective Deprotonation of Trialkylsilyl-protected Sulfoximines 1: Optimisation of Reaction Conditions

Entry	SM	Electrophile	Base	Solvent	T (°C)	Product	Yield (%)	ee (%)a
1	1a	Ph2CO	4•n-BuLi	Et2O	-78	2a	41	8
2	1a	Ph2CO	4•n-BuLi	Toluene	-78	2a	27	2
3	1b	TMSCl	4•s-BuLi	Et2O	-78	2b	41	7
4	1a	Ph2CO	5•LiCl	THF	-78	2a	70b	-42c
5	1b	TMSCl	5•LiCl	THF	-78	2b	72	36
6	1b	TMSCl	5•LiCl	THF	-94	2b	27	-54c
7	1b	TMSCl	5•LiCl	THF	-105	2b	58	61
8	1b	Ph2CO	6•LiCl	THF	-105	2c	41	38
9	1b	TMSCl	7•2LiCl	THF	-105	2b	53	0

^a Determined by HPLC using a chiral column. ^b Determined by NMR integration, all other yields refer to the amount of isolated product. ^c Denotes use of (R,R)-5 (S,S)-5 in all other cases.