Table 2. Catalytic studies of 1a, 2a, 3a, and Other PTC Catalysts toward MOMe (M = Li, Na, K).

entry	substrate	catalysta	conversionb (%)
1	NaOMe
2	NaOMe	NBu4Cl	44
3	NaOMe	18-crown-6	20
4	NaOMe	15-crown-5	39
5	NaOMe	ICy·HBF4	8
6	NaOMe	CDI(p-Tol)
7	NaOMe	1a	46
8	NaOMe	3a	43
9	NaOMe	2a	55
10	LiOMe	2a
11	KOMe	2a	5

^aCatalyst or catalyst precursor (see below).

^bAn aliquot was taken after 4 h to calculate conversion by ¹H NMR.