Table 2. Oxidation of the C–B bond catalysed by [(ICyD^Me)CuCl] complexes in water.

[Cu]	NEt3	% of 4 at 24 ha	% of 4 at 48 ha	% of 4 at 72 ha
1	1 equiv.	25	70	81
2	1 equiv.	47	91	>95
CuSO4	1 equiv.	55	87	>95
1	—	<5	<5	<5
2	—	12	13	13
CuSO4	—	<5	<5	6

^a% determined by ¹H NMR. For reactions with NEt₃ (fully homogeneous), the percentage represents the percentage of phenol (4) formed by comparison with the residual PhBpin (3). For reaction without NEt₃, which are heterogeneous due to the low solubility of 3, butadiene sulfone was used as an internal reference (see SI).