Table 1. Optimization of the Transition-Metal-Free Decarboxylative Iodination^a.

entry	R	base	1a	2a	1a′	2a′
1	Ag	–	14	0	74	10
2	K	–	9	90	2	trace
3	H	Li2CO3	89	11	trace	0
4	H	Na2CO3	76	23	trace	0
5	H	K2CO3	64	31	trace	0
6	H	Cs2CO3	57	38	trace	trace
7	H	K3PO4	4	93 (90)b	1	trace
8c	H	K3PO4	7	73	2	0
9d	H	K3PO4	62	34	0	0
10e	H	K3PO4	3	94	1	trace
11	H	–	94	0	2	0
12f	H	K3PO4	trace	0	23	72

^aReaction conditions: benzoic acid/benzoate (0.2 mmol), I₂ (0.6 mmol, 3.0 equiv), base (0.2 mmol, 1.0 equiv), MeCN (1.0 mL), 100 °C, 4 h.

^bYield in parentheses is of isolated material. Isolated as a mixture with 2a′ (2a:2a′ > 100:1).

^cI₂ (0.3 mmol, 1.5 equiv,), 170 °C, 16 h, 1,4-dioxane used as solvent.

^d1.0 equiv of H₂O added.

^eReaction performed in the dark.

^fI₂ was replaced with Br₂ to form the corresponding bromides Br-1a′ and Br-2a′.