Table 1.

Optimization of Cross Coupling^a

entry	mol % Ni	PhBX2 (equiv)	base	temp (°C)	yield (%)b	ee (%)c
1d	10	PhB(OH)2 (3.0)	CsF	100	14	n.d.e
2d	10	PhB(OH)2 (3.0)	K3PO4	100	14	n.d.e
3d	10	PhB(OH)2 (3.0)	NaOMe	100	78	n.d.e
4f	10	PhB(OH)2 (2.0)	NaOMe	100	93	54 (R)
5	10	PhB(OH)2 (2.0)	NaOMe	100	99	93 (S)
6	10	PhB(OH)2 (3.0)	NaOMe	70	83	99 (S)
7	10	PhB(OH)2 (3.0)	KOMe	70	74	69 (S)
8	10	PhB(OH)2 (3.0)	LiOMe	70	0	n.d.e
9g	5	PhB(OH)2 (2.5)	NaOMe	70	87	98 (S)
10g	5	(PhBO)3 (0.83)	NaOMe	70	98	97 (S)
11g,h	5	(PhBO)3 (0.83)	NaOMe	70	59	94 (S)
12g	0	PhB(OH)2 (2.5)	NaOMe	70	0	n.d.
13g	0	(PhBO)3 (0.83)	NaOMe	70	0	n.d.

^aConditions: pivalate 1a (0.10 mmol, 1.0 equiv), PhBX₂, Ni(cod)₂, base (2.0 equiv), PhMe (0.2 M), unless otherwise noted.

^bDetermined by ¹H NMR analysis using 1,3,5-trimethoxybenzene as internal standard.

^cDetermined by chiral HPLC. Absolute configuration of the major enantiomer in parentheses.

^dPerformed with racemic 1a. PCy₃ (24 mol %) added.

^en.d. = not determined.

^fPCy₂Ph (22 mol %) added.

^g0.4 M.

^h1.0 equiv H₂O added.