DBU-mediated [4 + 2] annulations of donor–acceptor cyclopropanes with 3-aryl-2-cyanoacrylates for the synthesis of fully substituted anilines

Abstract

The diversity-oriented synthesis of fully substituted aniline derivatives via the DBU-mediated [4 + 2] annulation of donor-acceptor 1,1-dicyanocyclopropanes with 3-aryl-2-cyanoacrylate has been developed.

Stereoselective Synthesis of 4,5‐Dihydroisoxazole Derivatives from 1,1‐Dicyanocyclopropanes and Hydroxylamine Hydrochloride

“…Thin layer chromatography (TLC) was used to monitor all reactions. These reported methods were used for the preparation of substituted cyclopropane‐1,1‐dicarbonitriles 7a – 7e , [97–112] other reagents and solvents were purchased from commercial suppliers and purified by standard techniques.…”

“…to construct various carbo‐ and heterocyclic compounds, containing many natural compounds and their analogs. As easily available multifunctional D‐A cyclopropanes, 2‐acyl‐3‐aryl‐cyclo‐propane‐1,1‐dicarbonitriles and 2‐acyl‐3‐aryl‐1‐cyanocyclopropane‐1‐carboxylates [84–96] have attracted wide attention in the classical heterocycle syntheses [97–112] . Considering the driving forces for the development of these new routes, and in continuation of using multifunctional D‐A cyclopropanes in the synthesis of diverse and complex compounds, we envisioned an approach to access functionalized isoxazoline derivatives through a cyclization reaction of substituted 1,1‐dicyanocyclopropane derivatives and hydroxylamine hydrochloride.…”

Synthesis and copolymerization of novel oxy ring-substituted isopropyl cyanoarylacrylates

“…The ECAA was also used in N,N'-dioxide-lanthanum(III)catalyzed asymmetric cyclopropanation with 2-bromomalonates [5]. It was employed in DBU-mediated [4 + 2] annulations of donor-acceptor cyclopropanes [6], in synergistic NaBH4 reduction/cyclization in synthesis of 3-oxabicyclo[3.1.0]hexane derivatives [7], as well as in studies on synthetic access to pyrano [3,2-c] quinoline and 3-substituted quinoline derivatives [8]. Benzyloxy ring-substituted ECAA was used in synthesis and biological evaluation of arylidene-thiazolidinediones with potential hypoglycemic and hypolipidemic activities [9].…”

Novel copolymers of vinyl acetate. 2. Oxy ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates

“…Ethyl p-butoxycinnamate was applied in maintaining self-renewal and pluripotency of stem cells [7]. 4-Phenoxy-substituted EOCP was used in DBU-mediated [4 + 2] annulations of donor-acceptor cyclopropanes with 3-aryl-2-cyanoacrylates for the synthesis of fully substituted anilines [8], as well as in preparation of azaindazoles as Btk kinase modulators [9]. Copolymers of oxy aryl-substituted EOCP with styrene were prepared earlier [10,11].…”