Table 1 Optimization of the reaction conditionsa.

From: Carbene and photocatalyst-catalyzed decarboxylative radical coupling of carboxylic acids and acyl imidazoles to form ketones

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Entry

Conditions

Yield [%]b

1

PC-1, A, 1a

Trace

2

PC-1, A, 1b

<5

3

PC-1, A, 1c

22

4

As entry 3, NHC = B

42

5

As entry 3, NHC = C

14

6

As entry 3, NHC = D

<5

7

PC-2, B, 1c

74

8

As entry 7, PC = PC-3

82 (78)c

9

As entry 7, PC = PC-4

76

10

As entry 7, PC = PC-5

8

11

As entry 7, PC = PC-6

78

12

As entry 8, without light irradiation

0

13

As entry 8, without PC

0

14

As entry 8, without NHC

<5

  1. aReaction conditions: 1 (0.15 mmol), 2a (0.10 mmol), PC (1 mol %), NHC (20 mol %), Cs2CO3 (2.0 equiv), MeCN (2.0 mL), blue LED (Kessil PR160 series, λmax = 427 nm), Ar atmosphere, 30–40 °C, 24 h. bNMR yields of reaction mixtures using 1,1,2,2-tetrachloroethane as internal standard. cIsolated yield is shown in parentheses.
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