Table 1.

Additions of Simple Thiols to Ynamides 1 and 2

RSH (equiv)	equiv AIBN	time	product	% yielda	(E:Z)b
n-BuSH (4)	2	3 h	3a	72	(15:1)
n-BuSH (1)	0.5	10 min	3a	76	(1:11)
PhSH (4)	2	5 h	3b	97	(33:1)
PhSH (1)	0.5	10 min	3b	33	(1:4.3)
t-BuSH (4)	2	6 h	3c	41	(Z only)c
n-BuSH (4)	2	3 h	4a	73	(8.4:1)
n-BuSH (1)	0.5	10 min	4a	72	(1:6.0)
PhSH (4)	2	5 h	4b	73	(8.5:1)
PhSH (1)	0.5	10 min	4b	74	(1:5.1)
t-BuSH (4)	2	6 h	4c	72	(1:5.2)

^aIsolated yield of the major isomer.

^bDetermined via ¹H NMR of the crude reaction mixture.

^cThe E isomer was not detected.