Palladium-Catalyzed Direct Arylation of Polyfluoroarenes for Accessing Tetra- ortho-Substituted Biaryls: Buchwald-type Ligand Having Complementary -PPh 2 Moiety Exhibits Better Efficiency.

Autor: Yuen OY; Department of Chemistry , The Chinese University of Hong Kong , Shatin, New Territories , Hong Kong.; Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong., Leung MP; Department of Chemistry , The Chinese University of Hong Kong , Shatin, New Territories , Hong Kong.; Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong., So CM; Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong., Sun RW; Guangzhou Lee & Man Technology Company Limited , 8 Huanshi Avenue South , Nansha, Guangzhou , Guangdong Province , China., Kwong FY; Department of Chemistry , The Chinese University of Hong Kong , Shatin, New Territories , Hong Kong.; Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hung Hom, Kowloon , Hong Kong.
Jazyk: angličtina
Zdroj: The Journal of organic chemistry [J Org Chem] 2018 Aug 17; Vol. 83 (16), pp. 9008-9017. Date of Electronic Publication: 2018 Jun 18.
DOI: 10.1021/acs.joc.8b01176
Abstrakt: The first general examples of direct C-H arylation of electron-deficient polyfluoroarenes with challenging di- ortho-substituted aryl(heteroaryl) chlorides for tetra- ortho-substituted biaryl synthesis are reported. Key to success is the use of Buchwald-type biaryl phosphine ligand, notably with inexpensive -PPh 2 moiety (instead of -PCy 2 group). Pd(OAc) 2 associated with ligand L9 exhibits even higher efficiency than the corresponding SPhos toward this reaction. A wide range of sterically hindered di- ortho-substituted chloroarenes bearing electron-donating or -withdrawing groups are found applicable. Excellent product yields are obtained under mild reaction conditions, and the catalyst loading down to 0.25 mol % of Pd can also be achieved.
Databáze: MEDLINE
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