Journal
ACS CATALYSIS
Volume 10, Issue 12, Pages 6682-6690Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acscatal.0c00220
Keywords
gold(I) catalysis; gold(III) catalysis; cycloaddition; enynal/enynone; reaction intermediates
Categories
Funding
- National Natural Science Foundation of China [21671066]
Ask authors/readers for more resources
Metal bound isobenzopyrylium species are proposed as reactive intermediates in transition-metal-catalyzed [3 + 2] or [4 + 2] cyclizations of o-alkynylbenzaldehydes (enynals) or o-alkynylarylketones (enynones). Because of their high reactivity, isolation and structural characterization of such intermediates have remained elusive. Herein, we report the isolation of such gold(I)and gold(III)-bound isobenzopyrylium intermediates, and two of them have been characterized by X-ray diffraction analysis. When reacting with reaction partners, such as styrene and phenyl acetylene, the Au(I) intermediate exhibited a reaction rate much faster than that of the Au(III) species. A degradation pathway of active Au(III)-carbene intermediate was observed, leading to release of Au(I) species and consequent formation of a dichloride compound. In other related catalytic reactions, the Au(I) intermediate could react well with a range of cyclization partners, whereas the Au(III) intermediate did not work. The above observations indicate that Au(I) species is probably the real catalyst in such gold-catalyzed transformations of o-alkynylbenzaldehydes and o-alkynylarylketones.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available