TABLE 4.

Cyclization Cascade of Substituted Vinyl (o-Azidophenyl)allenes To Furnish Indole and Pyrrole Products

						110 °Ca			hvb		hv/CuIc
entry	allenyl azide	R	R1	R2	R3	38d(%)	39d(%)	40d(%)	38d(%)	39d(%)	40d(%)	38d(%)	39d(%)
a	13a	CH3	H	H	H	40			56	24	20	42
b	13c	(CH2)2OTBS	H	H	H	52			43	24	16f	36
c	13d	t-Bu	H	H	H	57			20	53	38	59
d	13b	CH2OTBS	H	H	H	22			29	24	33	55	3
e	13e	CH3	Ph	H	H	40			30	44	31	67
f	13f	CH3	CH3	H	H	36			36	38	35	54
g	13g	Ph	CH3	H	H	47			39	23	11e,f	69f
h	23	CH3	H	CH2OTBS	H	24	34		decomp			decomp
i	25	CH3	H	TBS	H	33			7	25	9	44f
j	16a	CH3	H	Ph	H	(33)e	35		decomp			decomp
k	16c	CH3		–(CH2)3–	H	(36)e	40		not examined			not examined
l	16d	CH3		–(CH2)4–	H	36		51		32	27	54
m	24	CH3	CH3	(CH2)2OTBS	H	7		40		(20)e,g	(40)e,g	42g	(42)e,g
n	16b	CH3	Ph	Ph	Ph	45	21			51	31	53	26

^a100 mM in toluene.

^b254 nm in CH₃CN (5 mM).

^c254 nm in CH₃CN (5 mM), 150 mol % of CuI.

^dIsolated, chromatographically purified material.

^eNot isolated; estimated by integration of the ¹H NMR spectrum of the crude reaction mixture.

^fIrradiated at 300 nm.

^gIrradiated at 350 nm.