Table 2.

Scope of the intermolecular rhodium-catalyzed [2 + 2 + 2] carbocyclization reaction (Scheme 1; where R = H)

	1,6-Enyne 1a		5,6-Bicyclohexadiene 2
Entry	X =		Y/Y =		Yield (%)b
1	TsN	a	CO2Me	a	92
2	”	”	COPh	b	84
3	”	”	CONMe2	c	61
4	C(CO2Me)2	b	CO2Me	d	85
5	”	”	COPh	e	74
6	”	”	CONMe2	f	54
7	O	c	CO2Me	g	84
8	”	”	COPh	h	81
9	”	”	CONMe2	i	55

^aAll reactions were carried out on a 0.25 mmol reaction scale utilizing 10 mol% of Wilkinson's catalyst [RhCl(PPh₃)₃] modified with 20 mol% of silver triflate with the requisite 1,2-disubstituted alkyne (3 equiv.) under an atmosphere of argon.⁹

^bIsolated yield.