Table 2.

Initial Optimization of the asymmetric cyano-TMM cycloaddition with oxindoles.

entry	R	Additive	T, °C	Yield (%)	dr (47:48)	47, %ee	48, %ee
1	H	–	23	NDb	–	–	–
2	Me	–	23	91	1:1	91	53
3	PMB	–	23	60c	1:1	–	–
4	Ts	–	23	50	1:2	–	–
5	Boc	–	23	95	1:1.1	74	93
6	Ac	–	23	98	1:2.2	85	89
7	CO2Me	–	23	94	1:2.3	72	73
8	CO2Me	–	0	93	1:3	80	97
9	CO2Me	In(acac)3	0	98	1:3	82	98
10	CO2Me	(n-Bu)3SnOAc	0	96	1:3	81	96
11	CO2Me	(n-C6H13)4NCl	0	0	–	–	–

^aAll reactions were performed at 0.2 M in toluene with 1.5 equivalents 45, 2.5 mol% Pd₂(dba)₃•CHCl₃ and 10 mol% ligand for 12 hours. Yields were combined, isolated product; ee’s were determined by chiral HPLC.

^bComplex mixture.

^cConversion.