DABCO-catalyzed sp3 C–H activation: rapid access to isoxazole or coumarin-fused 3-quaternary carbon oxindoles and isoxazole-fused pyrrolidinones

Light-Triggered Catalytic Asymmetric Allylic Benzylation with Photogenerated C-Nucleophiles

Herein is reported the asymmetric allylic benzylation of Morita–Baylis–Hillman (MBH) carbonates with 2-methylbenzophenone (MBP) derivatives as nonstabilized photogenerated C-nucleophiles. The dual activation of both reaction partners, chiral Lewis-base activation of the electrophile and light activation of the nucleophile, enables the stereoselective installation of benzyl groups at the allylic position to forge tertiary and quaternary carbon centers.

Recent trends in catalytic sp3 C-H functionalization of heterocycles

Heterocycles are a ubiquitous substructure in organic small molecules designed for use in materials and medicines. Recent work in catalysis has focused on enabling access to new heterocycle structures by sp³ C-H functionalization on alkyl side-chain substituents-especially at the heterobenzylic position-with more than two hundred manuscripts published just within the last ten years. Rather than describing in detail each of these reports, in this mini-review we attempt to highlight gaps in existing techniques. A semi-quantitative overview of ongoing work strongly suggests that several specific heterocycle types and bond formations outside of C-C, C-N, and C-O have been almost completely overlooked.

Catalyst-free synthesis of 3-alkenyloxindoles from isatin-derived Morita–Baylis–Hillman carbonates

A variety of biologically and synthetically useful 3-alkenyloxindoles were rapidly synthesised via an SN2′-type allylic substitution reaction of isatin-derived Morita–Baylis–Hillman carbonates with sodium sulfinates. The syntheses were conducted under catalyst-free reaction conditions and good to excellent product yields (up to 96%) and Z/E selectivities (up to >20:1) were obtained.