Asymmetric synthesis of trifluoromethyl-substituted 3,3′-pyrrolidinyl-dispirooxindoles through organocatalytic 1,3-dipolar cycloaddition reactions

Abstract

A series of trifluoromethylated 3,3′-pyrrolidinyl-dispirooxindoles were constructedviaasymmetric [3 + 2] cycloaddition.

Highly Efficient and Diastereoselective Construction of Trifluoromethyl‐Containing Spiro[pyrrolidin‐3,2′‐oxindole] by a Catalyst‐free Mutually Activated [3+2] Cycloaddition Reaction

“…Probably, this equilibrium is difficult to monitor. According to the previous report on asymmetric exo′‐selective [3+2] cycloaddition reactions of CF 3 ‐containing isatin‐derived azomethine ylides with methyleneindolinones, the chiral amine catalyst played as a base catalyst to deprotonate CF 3 ‐containing isatin‐derived precursor . Thus, we still considered that vinylpyridine as a tertiary amine played the role of base catalyst in our case.…”

Spiro‐2‐oxindoles via 1,3‐dipolar cycloadditions. A decade update

“…), [66] while the latter gave further 25 examples with quite similar high cycloaddition outcome (Scheme 20). [70] …”

Phase‐Transfer Catalytic Strategy: Rapid Synthesis of Spiro‐Fused Heterocycles, Integrated with Four Pharmacophores‐Succinimide, Pyrrolidine, Oxindole, and Trifluoromethyl Group

“…N ‐2,2,2‐trifluoroethylisatin ketimine is a type of versatile reagent that it could act as nucleophile [12] or azomethine ylide precursor [13] in organic synthesis. Since it was firstly utilized in organocatalytic 1,3‐dipolar [3+2] cycloaddition with α,β‐unsaturated aldehydes for the formation of CF 3 ‐substituted spiropyrrolidinyl‐2,3′‐oxindoles by Wang′s group, [14] many kinds of canonical electron‐deficient alkenes had been employed as variants to react with this synthon, delivering large amount of more structurally diverse trifluoromethyl spiropyrrolidinyl‐2,3′‐oxindoles, such as nitroalkenes, [15] 3‐alkenyl‐5‐arylfuran‐2(3 H )‐ones, [16] 3‐alkylideneoxindoles, [17] α,β‐unsaturated ketone, [18] arylidene azlactone, [19] 5‐alkylidenerhodanine, [20] 5‐alkylidenethiazolones„ [21] barbiturate‐based olefin, [22] aurone olefin, [23] 4‐alkylidenepyrazolinones, [24] 2,3‐dioxopyrrolidine, [25] cyclic 2,4‐dienones [26] . However, these seminal studies all suffered from long reaction time, and this insuperable defect impeded their potential applications in the medicinal industry because of the high production costs.…”