N- and O-arylation reactions of pyridin-2-ones as ambidentnucleophiles have been achieved with diaryliodonium salts on the basis of base-dependent chemoselectivity. In the presence of N,N-diethylaniline in fluorobenzene, pyridin-2-ones were very selectively converted to N-arylated products in high yields. On the other hand, the O-arylation reactions smoothly proceeded with the use of quinoline in chlorobenzene
Formal Gold- and Rhodium-Catalyzed Regiodivergent C–H Alkynylation of 2-Pyridones
作者:Yunyun Li、Fang Xie、Xingwei Li
DOI:10.1021/acs.joc.5b02410
日期:2016.1.15
Formal regiodivergent C-H alkynylation of 2-pyridones bearing different N-substituents has been realized under Au(I) and Rh(III) catalysis using a hypervalent iodine alkyne reagent. When catalyzed by Au(I), the alkynylation occurred at the most electron-rich 5-position via an electrophilic alkynylation pathway. The selectivity was switched to the 6-position under assistance of an N-chelation group when a Rh(III) catalyst was employed. A rhodacylic complex has been isolated as a key intermediate.