Table 4. Chiral Boron Enolate Mannich Reactions^a.

entry	R1	product	yield [%]b	dr
1		15a	85	1:1
2		15b	74	2:1
3		15c	77	2:1
4	(–)–menthyl	15d	79	1.2:1
5	(–)–phenyl–menthyl	15e	85	6:1
6c	(–)–phenyl–menthyl	15e	89	10:1

^aReactions were run with 1.0 mmol B-Ph-9-BBN 1f, 1.0 mmol phenyl diazo ester 14, 1.0 mmol imine 3a, 5 mol % Cu(OTf)_2, in CH₂Cl₂ for 12 h under Ar, quenched with 5 equiv of methanol and Et₃N and stirring for another 5 h, followed by flash chromatography on silica gel.

^bIsolated yield.

^c1.0 mmol 1f, 1.1 mmol 14, 1.2 mmol 3a were used, reaction was run for 24 h under -20 °C.