Table 1.

Optimization of reaction conditions.

Entry a)	Catalyst	Yield (%) b)	Ratio of 4a:4a’ c)
1	CuCl@POL‐NHC‐Et	74	93:7
2	CuCl@POL‐NHC‐Cy	80	99:1
3	CuCl@POL‐NHC‐Ph	88	>99:1
4	CuCl@POL‐NHC‐BI	70	94:6
5	Cu(OTf)2@POL‐NHC‐Ph	38	96:4
6	CuCl2@POL‐NHC‐Ph	48	>99:1
7	CuBr@POL‐NHC‐Ph	trace	–
8 d)	CuCl‐NHC‐Ph	trace	–
9	CuCl@POL‐NHC‐PI	75	>95:5
10	POL‐NHC‐Ph	0	–

^a) Reaction conditions: 1a (0.5 mmol), 2a (2 equiv), 3a (1.5 equiv), NaO ^t Bu (1.5 equiv), [Cu]@POL‐NHC (20 mg), DMF (0.25 M), 60°C, 7 h;

^b) Isolated yield;

^c) Determined by using ¹H NMR spectroscopy;

^d) 4 mol% CuCl‐NHC‐Ph. The conversion rate of NHC in [Cu]@POL‐NHC is shown in Table S4 (Supporting Information).