Table 1.

Conditions Explored for Reaction Optimization^a

Entry	Additive	Yield of 1b	Yield of 1c
1	none	14%	18%
2	THF	13%	12%
3	18-crown-6	3%	2%
4	Ph3N	9%	13%
5	pyridine	7%	9%
6	1,10-phen	9%	1%
7	HMPA	9%	8%
8	benzophenone	32%	ND
9	benzophenoneb	57%	2%
10 c	benzophenone	72%	2%

^aOptimization was conducted on a 0.1 mmol scale. Yield was determined by ¹H NMR using mesitylene internal standard.

^b0.25 equiv of benzophenone.

^c2.5 equiv of TEMPO⁺PF₆⁻, 2.25 equiv of KHMDS, 0.45 equiv of benzophenone.