Table 2.

Isomerization of Allenamides at the α-Position.

entry	allenamides		conditions [time]a	dienes	yield [%]b		E:Zc
1		3	115 °C, 16 h		4	71	6:1
2		5a: R = n-Pr	135 °C, 6 h		8a	77	≥20:1
3		5a: R = n-Pr	CSA, 4 hd		8a	87	≥20:1
4		5b: R = Ph	135 °C, 16 h		8b	74	≥20:1
5		5b: R = Ph	CSA, 2 h		8b	83	≥20:1
6		5c: R = 2Nap	135 °C, 16 he		8c	73	≥50:1
7		5d: R = H	135 °C, 16 h		8d	69	-
7		6a: R = n-Pr	CSA, 10 min		9a	82	≥50:1
8		6b: R = Ph	CSA, 10 min		9b	76	≥50:1
9		6c: R = H	135 °C, 16 h		9c	69	-
10		7a: R = n-Pr	135 °C, 16 h		10a	62	≥50:1
11		7b: R = Ph	135 °C, 16 h		10b	82	≥50:1
12		11	135 °C, 16 h		12	45	≥20:1
13		11	CSA,f 2 h		12	61	≥20:1

^aUnless otherwise noted, CH₃CN was the solvent for thermal conditions, and CH₂Cl₂ was the solvent when using 10 mol % of CSA at rt. For all reactions, concn = 0.10 M.

^bIsolated yields.

^cDetermined by ¹H-NMR.

^dTemp started at −78 °C.

^eClCH₂CH₂Cl was used.

^f4 Å MS was used.