Table 1.

Nickel(II)-mediated conversion of 5 a to oxyesters.

Entry	Conditions[a]		Nucleophile	FC[b]
	NiCl2 [mm]	pH
1	10	8.2	50 % (v/v) TFE	–[d]
2	10	8.2	50 % (v/v) iPrOH	–[d]
3	10	8.2	10 % (v/v) MeOH	0.44
4	10	8.2	30 % (v/v) MeOH	0.70
5	10	8.2	50 % (v/v) MeOH	0.72
6	1	8.2	30 % (v/v) MeOH	0.69
7	20	8.2	30 % (v/v) MeOH	0.68
8	10	7.8	30 % (v/v) MeOH	0.61
9	10	8.6	30 % (v/v) MeOH	0.53
10[c]	10	8.2	30 % (v/v) MeOH	0.43
11	1	8.2	30 % (v/v) MeOH	0.59
12	10	8.2	30 % (v/v) MeOH	0.65

[a] Reactions were performed in 0.2 m HEPES buffer at 37 °C for 12 h in the presence of 1 mm of 5 a. [b] The fraction converted (FC) was determined by HPLC separation and integration (integ.) of 8 a (or 9) as a fraction of the sum of the integration of unreacted 5 a+hydrolyzed 6 a+8 a (or 9). [c] In the presence of 6 m Gn⋅HCl. [d] Oxyesters were not obtained.