Table 1.

Reaction Optimization.

Entry	Base	Temp, °C	% conv, 3	% ee, 4
1[a]	CsOAc	110	68	77
2[a–c]	CsOAc	90	61	55
3[a]	CsOAc	60	51	92
4[d]	AgOAc	70	90	88
5[b],[d]	AgOAc	60	78	92
6[d]	AgOCOCF3	70	78	91
7[d]	AgOCOCF3	60	77	92
8[d–e]	AgOCOCF3	70	59	93
9[b],[d];f]	AgOCOCF3	110	82	67

^[a]Toluene solvent.

^[b]Isolated yield.

^[c]Pivalic acid additive.

^[d]No solvent.

^[e]Pd(OCOCF₃)₂ catalyst.

^[f]Reaction time 12 h. See supporting information for details.