Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• . accomplished an asymmetric organocatalytic quadruple cascade reaction of various α-ketoamides 111 with aromatic α,β-unsaturated aldehydes 112 to obtain tetraaryl-substituted 2-azabicyclo[3.3.0]octadienones 114 in good yields (34–71%) with excellent diastereo- and enantioselectivities (84–97%). The reaction

• -unsaturated aldehydes. Asymmetric aza-Michael organocatalytic quadruple cascade reaction. Asymmetric synthesis of chiral 4-naphthylquinoline-3-carbaldehydes. Funding The authors express gratitude to the authorities of the IIS (deemed to be University), Jaipur, India for providing the necessary research

A quadruple cascade protocol for the one-pot synthesis of fully-substituted hexahydroisoindolinones from simple substrates

• Hong-Bo Zhang,
• Yong-Chun Luo,
• Xiu-Qin Hu,
• Yong-Min Liang and
• Peng-Fei Xu

Beilstein J. Org. Chem. 2016, 12, 253–259, doi:10.3762/bjoc.12.27

• one-pot cascade quadruple protocol features readily available starting materials, simple manipulation, mild conditions and good atom economy. Keywords: bifunctional catalysis; hexahydroisoindolinones; one-pot synthesis; quadruple cascade; Introduction Isoindolines and their congeners are one kind of

• generated through multicomponent quadruple cascade reactions, there is no report about the cascade synthesis of isoindolines in the past few decades [35][36][37][38][39][40][41][42][43][44][45][46], not mention the quadruple cascade synthesis of difficult fully-substituted hexahydroisoindolinones

• product is produced after the nucleophilic reaction, and the catalyst is regenerated (Scheme 3). Conclusion In summary, we have developed a one-pot quadruple cascade protocol to obtain fully-substituted hexahydroisoindolinones. This new, synthetic method is simple, efficient and atom-economic. This

Organocatalytic tandem Michael addition reactions: A powerful access to the enantioselective synthesis of functionalized chromenes, thiochromenes and 1,2-dihydroquinolines

• Chittaranjan Bhanja,
• Satyaban Jena,
• Sabita Nayak and
• Seetaram Mohapatra

Beilstein J. Org. Chem. 2012, 8, 1668–1694, doi:10.3762/bjoc.8.191

• acyclic α,β-unsaturated compounds In the previously reported organocatalytic tandem oxa-Michael–aldol reactions, the instantaneous dehydration of the β-hydroxyaldimine intermediates generates products with only one stereogenic center. Hong et al. [52] in 2009 reported a novel quadruple-cascade reaction

• quadruple-cascade reaction exemplifies an efficient three-component reaction. In 2010 Wang et al. [11] reported the highly enantioselective synthesis of trisubstituted chiral 4H-chromenes 20 through iminium-allenamide catalysis. The reaction consists of a Michael–Michael-cascade sequence between alkynals 5