Squaramide-catalysed asymmetric Michael addition/cyclization cascade reaction of 4-arylmethylidene-2,3-dioxopyrrolidines with 2-isothiocyanato-1-indanones

Abstract

A highly efficient cinchona alkaloid‐derived squaramide catalysed asymmetric Michael/cyclization cascade reaction of 4‐ arylmethylidene‐2,3‐dioxopyrrolidines with 2‐isothiocyanato‐1‐indanones was successfully developed. This protocol provides an efficient and mild access to obtain indanone‐derived...

Bifunctional Squaramide‐Catalyzed Asymmetric [3+2] Annluation Reactions of 2‐Isothiocyanato‐1‐indanones with 2‐Arylidene‐1,3‐indanediones

“…In 2021, Du's group developed a new strategy for the preparation of bisspiro pyrrolidine derivatives with three chiral centers by the reaction of 2-isothiocyanato-1-indanones and 2,3-pyrrolidinediones with chiral squaramide catalyst (Scheme 1, b). [10] Notably, this is the first instance of this substrate participating in an asymmetric Michael/cyclization reaction. Herein, we designed bifunctional squaramide-catalyzed asymmetric [3 + 2] annulation reactions of 2-arylidene-1,3-indanediones with 2-isothiocyanato-1-indanones…”

“…2‐Arylidene‐1,3‐indanediones could easily participate in the Michael reaction as reaction acceptors, which made the reaction proceed smoothly. In 2021, Du′s group developed a new strategy for the preparation of bisspiro pyrrolidine derivatives with three chiral centers by the reaction of 2‐isothiocyanato‐1‐indanones and 2,3‐pyrrolidinediones with chiral squaramide catalyst (Scheme 1, b) [10] . Notably, this is the first instance of this substrate participating in an asymmetric Michael/cyclization reaction.…”

Annulations involving 1-indanones to access fused- and spiro frameworks

“…The authors also synthesized spiropyrrolidone indanone scaffolds using squaramide catalyst 156 using readily available 4-arylmethylidene-2,3-dioxopyrrolidines 155 and 2isothiocyanato-1-indanones 72. 77 This method provides mild access to bispirocyclic compounds 157 containing three contiguous stereocenters in excellent yields (up to 99%) and enantio-/diatereoselectivity (up to 99% ee, >20 : 1 dr). Very recently, an efficient synthesis of bispirocyclic saccharine system is realized involving asymmetric [3+2] spiroannulation reaction of saccharine-derived cyclic azadienes 167 with 2-hydroxy-1-indanones 163.…”

Recent Advances of Michael/hetero‐Michael Addition Reaction in the Synthesis of 3‐Nitro‐2H‐chromene Derivatives

“…In modern organic synthesis, it plays a crucial role in furnishing a huge number of key precursors of natural products and important bioactive compounds [1–5] . So, several Michael donors and activated Michael acceptors have been discovered which brings out a new revolution regarding the synthesis of various carbo‐ and heterocyclic structures by utilizing this important transformation over the last decades [6–14] . Amongst the various Michael acceptors used, 3‐nitro‐2 H ‐chromene and its derivatives have received considerable attention from many researchers due to its bioactivity, reactivity, and easy accessibility [15–18] .…”