An Investigation of the Reaction of 2-Aminobenzaldehyde Derivatives with Conjugated Nitro-olefins:  An Easy and Efficient Synthesis of 3-Nitro-1,2-dihydroquinolines and 3-Nitroquinolines

Abstract

2-Aryl-3-nitro-1,2-dihydroquinolines 3 were prepared from the reaction of beta-nitrostyrenes 2 and 2-aminobenzaldehyde 1 in the presence of DABCO. Not only beta-nitrostyrenes but other alkyl nitro olefins also can be used in this reaction as well. When DDQ or silica gel was added to a solution of 3-nitro-1,2-dihydroquinolines 3, 3-nitro-2-substituted-quinolines 4 were obtained. When 2-aminobenzaldehyde derivatives 7 and 12 were reacted with beta-nitrostyrenes 2, unique rearrangement products were produced.

A Theoretical Evaluation of the Michael‐Acceptor Ability of Conjugated Nitroalkenes

“…We then decided to evaluate some of the experimental results available in the literature on the Michael-type addition of various carbon-and heteroatom-centered nucleophiles to conjugated nitroalkenes. The representative examples chosen from the literature involve reactions of nitroalkenes with heteroatom nucleophiles (2-aminobenzaldehyde), [39] Ccentered nucleophiles (indole and malonate), [40,41] and an organometallic reagent (Fischer aminocarbene complex). [42] Our analysis has shown that the parameters discussed above [local softness (s + β-C ), the β-CED and Fukui function (f + β-C )] correlate well with the isolated yields in a majority of the cases and moderately well with the reaction time (see Supporting Information for further discussion).…”

Organocatalyzed Synthesis of Functionalized Quinolines

“…In 2004, Yan et al . employed 1,4‐Diazabicyclo[2.2.2]octane (DABCO) to obtain 2‐substituted‐3‐nitro‐1,2‐dihydroquinolines with the use of alkyl or aryl nitro olefins and 2‐aminobenzaldehydes.…”

“…In 2004, Yane tal. [41] DABCO has been used to promote o-alkynylaryl isocyanides and alcohols to offer functionalized quinolines by Zhao and co-workersfurther in 2010 (Scheme 26). [42] l-proline is frequently used as organocatalyst in organic transformations, and the utility of l-proline in quinoline synthesis has also been wellr eported.…”

Copper‐Catalyzed Synthesis of 3‐NO2 Quinolines from o‐Azidobenzaldehyde and Nitro‐olefins and its Application in the Concise Synthesis of Quindolines

“…In general, the direct nitration of quinolones was considered as the most direct synthetic method, but this process often affords 3‐nitroquinoline N ‐oxides as the major nitrification product. Moreover, the cycloaddition between 2‐aminobenzaldehyde and nitro‐olefins in alkaline conditions followed by oxidation using 2,3‐dicyano‐5,6‐dichlorobenzoquinone (DDQ) or silica gel could serve as alternative methods for 3‐ nitroquinolines synthesis, but the 2‐aminobenzaldehyde could readily undergo self‐condensation, which resulted in poor yields and limited applications . Therefore, the development of effective methods for the facile construction of 3‐nitroquinoline is highly desirable.…”