Selective [3 + 2] C-H/C-H Alkyne Annulation via Dual (Distal) C_(β, δ)-H Bond Activation Relay: A Novel Therapeutic Quinazolone-Tethered Benzofulvenes for Oral Cancer.

ABSTRACT: In contrast to proximal C-H bond activations, distal C-H bond activation is fundamentally more challenging and requires distinctly specialized directing partners or techniques. In this context, we report an unprecedented dual (distal) β-C(benzylic)-H and δ-C(aryl)-H bond activation relay protocol for the chemo-, regio-, and stereoselective construction of heterocycle-tethered benzofulvenes via [3 + 2] CH/CH-alkyne annulation under palladium catalysis. The protocol overrides the more favorable [4 + 2] CH/NH annulation and does not follow the vinylic C-H bond activation pathway. Mechanistic studies provide insight into the favored cyclopalladation of key intermediates (resulting from β-C(benzylic)-H bond cleavage) through relay δ-C(aryl)-H cleavage (vs N-H cleavage) prior to reductive elimin

SUBMITTER: Satpute DP 

PROVIDER: S-EPMC11600166 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature