Science of Synthesis

Zhang, H.; Liu, C.; Lei, A., Science of Synthesis: Catalytic Transformations via C—H Activation, (2015) 2, 144.

N-Heterocyclic carbene–gold(I) hydroxide complexes with 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) as ligand can catalyze the carboxylation of carbo- and heterocycles ‌12‌ with high regioselectivity at the most acidic C—H bond position to form the corresponding carboxylic acids ‌13‌ (‌Scheme 8‌).[‌20‌] Various hetarenes such as oxazoles, thiazoles, and substrates containing three or four heteroatoms work well under the standard reaction conditions. Activated arenes are converted into their corresponding carboxylic acids in excellent yields with high regioselectivity.

‌Meeeee 8‌ Meee-Meeeeeeee M—M Meeeeeeeeeeee ee Meeeeeeee eee Meeeeeeee Meeeee eeee Meeeee Meeeeee[‌88‌]

‌Meeeeeeeeee 8‌

Me8	Meeeee (%)	Mee
	88	[‌88‌]
	88	[‌88‌]
	88	[‌88‌]
	88	[‌88‌]
	88	[‌88‌]
	88	[‌88‌]
	88e	[‌88‌]
	88e	[‌88‌]
	88e	[‌88‌]
	88	[‌88‌]
	88	[‌88‌]
	88	[‌88‌]
8,8,8,8-M8M8M	88 (88)e	[‌88‌]
8,8,8-M8M8M8	88	[‌88‌]
8,8-M8M8M8	88	[‌88‌]
8,8,8,8-Me8M8M	88 (88)e	[‌88‌]
8,8,8-Me8M8M8	88	[‌88‌]
8,8-Me8M8M8	88	[‌88‌]

e Meeeeeee eeeeee.

e Meeee 8,8-eee(8,8-ee-eeee-eeeeeeeeeee)eeeeeeee-8-eeeeeee ee M-eeeeeeeeeeee eeeeeee eeeeee.

e Meeeeeee eeeee ee eee eeeeeeeeeeeeee eeeeeee eeeee 8 eeeee ee MMM ee eeeeeeeeeee.

Meeeeeeee, M-eeeeeeeeeeee eeeeeee–eeeeee(M) eeeeeeeee eeeeeeeee eeeeee eee eeeeeeeeeeeeee eeeeeeeeeeeee ee eeeeeeee M—M eeeee ee eeeeeeeee eee eeeeeeeee eeeeee ‌88‌ ee eeee eee eeeeeeeeeeeee eeeeeeeeee eeeee ‌88‌ (‌Meeeee 8‌).[‌88‌]

‌Meeeee 8‌ Meeeee-Meeeeeeee M—M Meeeeeeeeeeee ee Meeeeeeee eee Meeeeeeee Meeeee eeee Meeeee Meeeeee[‌88‌]

‌Meeeeeeeeee 8‌

Me8	Meeeee (%)	Mee
	88	[‌88‌]
	88	[‌88‌]
	88	[‌88‌]
8,8,8-M8M8M8	88	[‌88‌]
8,8,8,8-M8M8M	88 (88)e	[‌88‌]

e Meeeeeee eeeeee.

e Meeeeeee eeeee ee eee eeeeeeeeeeeeee eeeeeee eeeee 8.8 eeeee ee MeMM ee eeeeeeeeeee.

Meeeeeeeeeee Meeeeeeee

Meeeeeee- eee Meeeeeeeeeeeeee Meeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeee eee eeeeeee eeee e eeee ee Me(MM)(MMe) (8.8 ee, 8.888 eeee) eee MMM (88.8 ee, 8.88 eeee) ee MMM (8.8 eM) eeeee MM8 (8.8 eee). Mee eeeeeee eee eeeeeeeee eee 88 eee ee 88 °M eeee eeeeeeee eeeeeeee (8888 eee). M eeee ee eee eeeeeeee eeeeeeeee ‌88‌ (8 eeee) ee MMM (8.8 eM) eee eeeeeeeeee eee MM8 eeeeeee eeeeeee. Mee eeeeeeee eee eee ee 88 °M eee 88 e, eee eeee eeeeeeee eeee 8 M ee MMe (8 eM). Mee eeeeeee eee eeeee ee eeee MeMMe (8 × 8 eM) eee eee eeeeeeee eeeeeee eeeeeeee eeee eeeeee eeee 88% ee MeMe (8 eM), eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee/MeMMe 8:8) eeeeeeee eee eeeeeeeeeeeee eeeeeeeeee eeee.

Meeeeeee- eee Meeeeeeeeeeeeee Meeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

M eeee eee eeeeeee eeee e eeee ee Me(MM)(MMe) (88.8 ee, 8.88 eeee) eee MeMM (888.8 ee, 8.8 eeee) ee MMM (8.8 eM) eeeee MM8 (8.8 eee). Mee eeeeeee eee eeeeeeeee eee eeeee 88 eee ee 88 °M eeee eeeeeeee eeeeeeee (8888 eee). M eeee ee eee eeeeeeee eeeeeeeee ‌88‌ (8 eeee) ee MMM (8.8 eM) eee eeeeeeeeee eeeeeee e MM8 eeeeeee eeeeeee. Mee eeeeeeee eee eee ee 88 °M eee 8 e, eeee eeeeeeee eeee MMe (8 eeee). Mee eeeeeee eeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeeee ee MeMMe (8 eM), eeeeee eeee 88% ee MeMe (8 × 8 eM), eee eeeee (Me8MM8). Meeeeeeee eeee eeeeeee eeeee eeeeeee eeeeeeee ee eeeeee eee eeeeeeeeee eeeee.

References