Recent Advances in Lewis Base‐Catalysed Chemo‐, Diastereo‐ and Enantiodivergent Reactions of Electron‐Deficient Olefins and Alkynes

Abstract

This review is dedicated to Prof. You Huang on the occasion of his 60 th birthday.

Unveiling a family of spiro-β-lactams with anti-HIV and antiplasmodial activity via phosphine-catalyzed [3+2] annulation of 6-alkylidene-penicillanates and allenoates

“…It is known that phosphine-catalyzed [3+2] annulations of allenoates with electron-deficient alkenes are an effective strategy for the synthesis of cyclopentene derivatives (Guo et al, 2018;Meng et al, 2022;Song et al, 2022). In the presence of phosphines, allenoates act as three-carbon synthons giving regioisomeric cyclopentenes upon formal [3+2] cycloaddition with asymmetrically substituted alkenes.…”

Substrate-Controlled Diversity-Oriented Synthesis of Novel Polycyclic Frameworks via [4 + 2] and [3 + 2] Annulations of Ninhydrin-Derived MBH Adducts with 3,4-Dihydroisoquinolines

“…Among them, the Morita-Baylis-Hillman (MBH) adducts and their derivatives have been extensively explored due to their multifunctional features, and applied as versatile synthons in diverse annulation reactions, mostly for the construction of polycyclic frameworks via cycloaddition with a large variety dipolarophiles [28][29][30][31][32][33]. In particular, isatins or aldehydes-derived MBH carbonates can act as valuable C1, C2, C3, or C4 synthons, which in situ generated zwitterionic allylic ylide species under Lewis base catalysis [34][35][36][37] or π-allyl metal complexes [38][39][40][41][42][43][44][45], to exhibit universal building blocks for the construction of multifunctional and potentially biologically active ring structures via various [3 + n] [46][47][48][49][50][51][52][53], [2 + n] [54][55][56][57][58], [1 + n] [59][60][61][62][63] annulation reactions. As a result, in the past few years, these annulations of employing the isatin or aldehydes-derived MBH carbonates as substrates have evolved into an extremely vibrant research area and achieved great progress and developments.…”

Palladium-catalyzed asymmetric (4 + 3) cycloaddition of N-2,2,2-trifluoroethylisatin ketimines: access to optically active spirooxindoles

“…This is why no examples involving palladium-catalyzed asymmetric cycloaddition of N -2,2,2-trifluoroethylisatin ketimines have been realized. As part of our continuous efforts on cycloaddition reactions, 7 we herein disclose the first Pd-catalyzed enantioselective (4 + 3) cycloaddition of N -2,2,2-trifluoroethylisatin ketimines with 2-methylidenetrimethylene carbonate. 8 The well-optimized reaction conditions ensured that the highly enantioenriched products were obtained in the absence of an additional base.…”