Table 5.

Diyne scope in the asymmetric addition to aldehydes^a

entry	aldehyde	R2	product	% yieldb	% eec
1			3a	76	65
2			3b	73 (49)d	82 (79) d
3d			7a	93	97
4e			7b	85	88
5e			7c	90	87
6			7d	98	91
7			7e	77	73
8			7f	>99	88

^aReaction performed with 1 equiv of aldehyde and 3 equiv of diyne donor.

^bIsolated yields.

^cEnantiomeric excess determined by chiral HPLC.

^dReaction was performed with 2 equiv of diyne and Me₂Zn.

^eCatalyst loading was increased to 20 mol% 1 and 40 mol% TPPO.