Table 1. Condition Screening for the MCC-McP-Au⁰-Catalyzed Cycloisomerization of Alkynoic Acids^a.

entry	solvent	temp (°C)	time (h)	conversion (%)b
1	CH2Cl2	RT	96	33
2	CH2Cl2	40	24	20
3	toluene	90	23	99
4	dioxane	90	23	81
5	CH3CN	90	23	99
6c	toluene	90	23	0
7d	toluene	90	23	2

^aReaction conditions unless specified otherwise: 1a (0.4 mmol), MCC-McP-Au⁰ (5 mg, 0.32 mol % Au⁰), solvent (1 mL).

^bConversion to 2a as determined by ¹H NMR using 1,4-dinitrobenzene as internal standard.

^cReaction performed with MCC-sulfonic acid propyl silane (MCC-Si-CH₂CH₂CH₂SO₂H).

^dReaction performed using MCC-McP-Au⁰/Au^I (cf. Figure 1c) as catalyst.