TY - JOUR
T1 - 5-Position-selective C-H trifluoromethylation of 8-aminoquinoline derivatives
AU - Kuninobu, Yoichiro
AU - Nishi, Mitsumi
AU - Kanai, Motomu
N1 - Funding Information:
This work was supported in part by ERATO from JST, Grant-in-Aid for Scientific Research (B) and Grant-in-Aid for Challenging Exploratory Research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan, and Yakugaku Shinkoukai.
PY - 2016
Y1 - 2016
N2 - We developed a copper-catalyzed 5-position-selective C-H trifluoromethylation of 8-aminoquinoline derivatives. The reaction proceeded with high functional group tolerance under mild conditions. In the case of quinolines with an amide, carbamate, urea, or sulfonamide group at the 8-position of quinoline moieties, a radical scavenger experiment indicated that the reaction proceeded via a radical pathway. The protecting group of an 8-amidoquinoline derivative could be removed by hydrolysis. On the other hand, the trifluoromethylation of 8-aminoquinolines was also promoted by other Lewis acids as well as a copper catalyst and proceeded even in the presence of a radical scavenger. These results indicated that the trifluoromethylation of 8-aminoquinolines proceeded via a Friedel-Crafts-type reaction. Interestingly, the copper salt works as either a catalyst for the formation of a CF3 radical or a Lewis acid to promote a Friedel-Crafts-type reaction, depending on the substrate.
AB - We developed a copper-catalyzed 5-position-selective C-H trifluoromethylation of 8-aminoquinoline derivatives. The reaction proceeded with high functional group tolerance under mild conditions. In the case of quinolines with an amide, carbamate, urea, or sulfonamide group at the 8-position of quinoline moieties, a radical scavenger experiment indicated that the reaction proceeded via a radical pathway. The protecting group of an 8-amidoquinoline derivative could be removed by hydrolysis. On the other hand, the trifluoromethylation of 8-aminoquinolines was also promoted by other Lewis acids as well as a copper catalyst and proceeded even in the presence of a radical scavenger. These results indicated that the trifluoromethylation of 8-aminoquinolines proceeded via a Friedel-Crafts-type reaction. Interestingly, the copper salt works as either a catalyst for the formation of a CF3 radical or a Lewis acid to promote a Friedel-Crafts-type reaction, depending on the substrate.
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U2 - 10.1039/c6ob01325b
DO - 10.1039/c6ob01325b
M3 - Article
AN - SCOPUS:84984661272
VL - 14
SP - 8092
EP - 8100
JO - Organic and Biomolecular Chemistry
JF - Organic and Biomolecular Chemistry
SN - 1477-0520
IS - 34
ER -