Table 1. Optimization of the reaction conditions for the asymmetric dearomative borylation ^a .

Entry	Ligand	1: R	Yield b (%)	d.r. c	ee d (%)
1	L1	1a: Me	Trace	n.d.	n.d.
2	L2	1a: Me	Trace	n.d.	n.d.
3	L3	1a: Me	44	45 : 55	92
4	L4	1a: Me	60	80 : 20	80
5	L5	1a: Me	90	92 : 8	86
6	L5	1b: Et	86	>98 : 2	91
7	L5	1c: iPr	93	94 : 6	94
8	L5	1d: tBu	72	97 : 3	81
9 e	L5	1c: iPr	46	50 : 50	96
10 f	L5	1c: iPr	55	63 : 37	97
11 g	L5	1c: iPr	56	70 : 30	97
12 h	L5	1c: iPr	85	95 : 5	95

^aUnless otherwise noted, all the reactions were carried out with 1 (0.2 mmol), L (0.02 mol), CuCl (0.02 mmol), NaOMe (0.02 mmol), alcohol (0.4 mmol), and B₂pin₂ (0.3 mmol) in toluene (1 mL) at 25 °C for 16 h.

^bThe yield of isolated cis-product 2.

^cThe diastereoselective ratio (cis/trans) was determined by ¹H NMR of crude reaction mixtures.

^dThe enantiomeric excess was determined by HPLC on a chiral IE column.

^eMeOH was used instead of tBuOH.

^fEtOH was used instead of tBuOH.

^g iPrOH was used instead of tBuOH.

^hThe reaction was carried out at 0 °C for 18 h.