Synthesis of Quinoline and Quinolin-2(1H )-one Derivatives via Nickel Boride Promoted Reductive Cyclization

A mild and efficient approach for the synthesis of diversely substituted quinoline and quinolin-2-one derivatives is disclosed. In situ generated nickel boride proved to be an effective promoter of the reductive cyclization reaction. Broad substrate scope, mild reaction conditions, consistent yield, and a wide range of functional group tolerance are the other notable features of the newly discovered reaction. A large number of quinoline and quinolin-2-one derivatives may be prepared from milligram to multigram scale employing this intramolecular reductive cyclization protocol.

Automated summary

A mild and efficient method for synthesizing diverse substituted quinoline and quinolin-2-one derivatives was reported. In situ generated nickel boride proved to be an effective catalyst for the reductive cyclization reaction. The reaction exhibited broad substrate scope, mild conditions, consistent yield, and was tolerant to a wide range of functional groups. This intramolecular reductive cyclization protocol enables the preparation of a large number of quinoline and quinolin-2-one derivatives from milligram to multigram scale.