Control of Activation Mode To Achieve Diastereodivergence in Asymmetric Syntheses of Chiral Spiropiperidinone Derivatives

Organocatalytic Asymmetric [4 + 2] Cyclization of Azadienes with Azlactones: Access to Chiral 3-Amino-δ-Lactams Derivatives

Herein, a series of chiral δ-lactam frameworks have been synthesized and catalyzed by chiral phosphoric acid (CPA) utilizing two kinds of open-chain aza-dienes and azlactones derived from amino acids. This powerful [4 + 2] annulation produces a broad substrate scope with functional group tolerance in yield up to 97% with up to 98:2 er. Moreover, a facile scale-up and straightforward conversion to diversely substituted products verify the synthetic utility of this method featuring good compatibility and high efficiency.

Anion Cascade Reactions II: Synthesis of 3-Isoquinuclidone-Based Bridged Polycyclic Lactams

A facile and convenient anion cascade strategy was developed for the synthesis of bridged-ring amides in moderate to excellent yields in one step in the presence of tBuOK in EtOH under mild conditions, starting from various cheap and commercially available 2-cyanoacetamides and precisely designed straight-chain and annular 1,4-dienones. This simple protocol was generally applicable to a wide range of substrates with high chemical conversion and diastereoselectivity.

Protecting group-directed annulations of tetra-substituted oxindole olefins and sulfur ylides: regio- and chemoselective synthesis of cyclopropane- and dihydrofuran-fused spirooxindoles

Protecting group-controlled annulations of tetra-substituted oxindole olefins and sulfur ylides have been achieved for the synthesis of multifunctional cyclopropane- and dihydrofuran-fused spirooxindoles. Under precise annulation regulation, a variety of cyclopropane- and dihydrofuran-fused spirooxindoles containing vicinal quaternary carbon centers were produced in up to 90% yield with up to 20 : 1 dr. This reaction demonstrates high regio-, chemo- and diastereoselectivity, broad functional group tolerance and gram-scale capacity.

Highly enantioselective synthesis of fused bicyclic dihydropyranones via low-loading N-heterocyclic carbene organocatalysis

Highly diastereo and enantioselective [4+2] cycloadditions have been achieved between pyrrolidone-derived cyclic enones and α-haloaldehydes under mild conditions. Relying on extremely reactive in-situ generated chiral N-heterocyclic carbenes, this stereoselective annulation proceeds efficiently even on the gram scale with the catalyst loading as low as 0.025 mol% (250 ppm). A variety of cis-substituted bicyclic dihydropyranones can be produced in up to 96% yield with up to >99% ee. In addition, simple, inexpensive linear aldehydes such as n-propanal can be used directly in asymmetric cycloadditions via oxidative N-heterocyclic carbene organocatalysis with low catalyst loading. This method may provide an economical and practical approach for the asymmetric synthesis of medicinally relevant molecules.

Diastereo- and enantioselective phase-transfer alkylation of 3-substituted oxindoles with racemic secondary alkyl halides

A catalytic asymmetric alkylation of fully substituted enolates with racemic, non-activated secondary alkyl halides is described.

Drug design based on pentaerythritol tetranitrate reductase: synthesis and antibacterial activity of Pogostone derivatives

We performed molecular docking studies of Pogostone with PETNR and analyzed structure–activity relationships, which guided the structure design and the subsequent facile organocatalytic synthesis of Pogostone derivatives.