Copper Catalyzed Synthesis of 3‐Nitro‐Quinolines from Nitro‐Olefins and Anthranils: Its Application in the Synthesis of Quindoline

Abstract

Copper-catalyzed routes have been achieved for the synthesis of 3-nitroquinolines from readily available nitroolefins and anthranils. This reaction proceeds via the [4 + 2] cycloaddition between anthranils and nitro-styrenes under mild reaction conditions to obtain biologically important heterocycles. A wide range of diversely substituted nitro-olefins and anthranils are successfully employed in this reaction to access a series of 3-nitroquinolines in 81-93% yields. The synthetic utility of the present methodology is also illustrated in this manuscript.

Rh(III)-Catalyzed Tandem Reaction Access to (Quinazolin-2-yl)methanone Derivatives from 2,1-Benzisoxazoles and α-Azido Ketones

“…In addition, no reaction occurred when 1a was subjected to the standard conditions (Scheme c), showing that the rhodium catalyst is not inserted into the N–O bonds of 2,1-benzisoxazoles, which does not undergo ring-opening during the reaction. The result excludes the possibility that 1-(2-aminophenyl)­ethan-1-one is involved in this transformation …”

“…The result excludes the possibility that 1-(2-aminophenyl)ethan-1-one is involved in this transformation. 14 According to the above-mentioned experimental results, a plausible reaction mechanism for the Rh(III)-catalyzed tandem reaction is proposed as shown in Scheme 5 (using 3aa as an example). Initially, treatment of a rhodium catalyst with AcOH leads to the formation of reactive rhodium(III) species A via ligand exchange.…”

Synthesis of 4-styrylquinolines via direct oxidative C3-alkenylation of anthranils under Pd(ii) catalysis

“…11 b , c While these methods offer convenient routes to obtain 4-styrylquinolines, the reliance on expensive catalysts presents a significant drawback to these approaches. To address these limitations and in continuation of our interest in anthranil chemistry, 12 herein we present a palladium-catalyzed, regio- and stereoselective oxidative C3-alkenylation of anthranils with vinyl arenes (eqn (1d)), enabling the synthesis of various substituted ( E )-3-styrylbenzo[ c ]isoxazoles. Additionally, we explored the reactivity of 3-styrylbenzo[ c ]isoxazoles in diverse [4+2]-cycloaddition reactions with a dienophile, leading to the construction of a wide range of substituted E -styryl quinolines.…”