Table 3.

Synthesis of β-ketoenamides KE57–77 by the LANCA three-component reaction of lithiated 2-(trimethylsilyl)ethoxyallene, nitriles (R²-CN) and carboxylic acids (R³-CO₂H) according to Scheme 4.^a

entry	R1	R2	R3	product	yield	ref.
1	2-THP	cPr	cPr	KE57	24%	[42]
2	TMSE	cPr	cPr	KE58	75%	[42]
3	TMSE	cPr	CH=CH-Ph	KE59	57%	[30]
4	TMSE	t-Bu	Me	KE60	52%	[42]
5	TMSE	t-Bu	CF3	KE61	14% (+28% PY)	[33]
6	TMSE	t-Bu	HC=CH2	KE62	40%	[43]
7	TMSE	t-Bu	HC=CH-Me	KE63	42%	[43]
8	TMSE	t-Bu	HC=CH-Ph	KE64	35%	[43]
9	TMSE	t-Bu	HC=CH-C6H4-NO2	KE65	52%	[43]
10	TMSE	t-Bu	HC=CH-2-Fu	KE66	30%	[43]
11	TMSE	t-Bu	Ph	KE67	49%b	[30]
12	TMSE	Ad	cPr	KE68	57%	[42]
13	TMSE	Ph	CF3	KE69	39% (+24% PY)	[42]
14	TMSE	Ph	HC=CH-Me	KE70	46%	[43]
15	TMSE	Ph	HC=CH-Ph	KE71	50%	[43]
16	TMSE	Ph	C≡CH	KE72	21%	[42]
17	TMSE	Ph	Ph	KE73	36%	[29]
18	TMSE	Ph	2-Py	KE74	24%	[42]
19	TMSE	Ph	2-Th	KE75	75%	[42]
20	TMSE	Ph	Ac	KE76	28%	[42]
21	TMSE	2-Th	Ph	KE77	74%	[29]

^aAbbreviations: THP = tetrahydropyranyl, Ad = 1-adamantyl, Fu = furyl, Py = pyridyl, Th = thienyl; all alkenyl substituents are E-configured. ^bAs second product, 15% of the imine tautomer of β-ketoenamide KE67 was isolated.