Table 1.

Mercury-catalyzed IFCA reaction of 5a

Entry	HgX2, (equiv)	Conditions	Yield %,a (trans:cis)b
1	Hg(OTf)2, (0.005)	PhMe, rt, 1.5 h; 48 °C, 25 h	40%,d 12.5:1
2	Hg(OTf)2, (0.005)	PhMe, rt, 20 min; 60 °C, 25 h	54%,d 8:1,
3	Hg(OTf)2, (0.005)	PhMe, 45 °C, 4 h	54%, 9:1
4	Hg(OTf)2, (0.005)	PhMe, 55 °C, 4 h	50%, 9:1
5	Hg(OTf)2, (0.005)	PhMe, 110 °C, 10 min	34%, <9:1
6	Hg(OTf)2,(0.01)c	PhMe, 60 °C, 30 min; 110 °C, 12 hc	0
7	Hg(OTf)2, (0.005)	MeCN, rt, 20 min; 70-80 °C, 19 h	0
8	Hg(OTf)2, (0.005)	CH2Cl2, rt, 35 min; 90 °C, 5 h	13%,d 12.5:1
9	Hg(OTf)2, (0.005)	ClCH2CH2Cl, rt, 35 min; 90 °C, 5 h	27%,d 15:1
10	Hg(SO3C4F9)2, (0.005)	PhMe, rt, 24 h; 80 °C, 15 min	e

^aYields are for isolated products unless otherwise stated.

^bThe diastereomeric ratio was determined by analysis of the ¹H NMR spectrum of the crude reaction mixture.

^c2,6-di-tert-butylpyridine was added.

^dCrude yield.

^eA complex mixture was formed.