The construction of N-heterocyclic eight-membered rings with good regio-, stereo-, and enantioselective control remains a formidable challenge in asymmetric catalysis. Herein, we report a palladium-catalyzed asymmetric [4 + 4] cycloaddition of anthranils with γ-methylidene-δ-valerolactones in the presence of Et3B, delivering highly functionalized tetrahydrobenzo­[b]­azocine derivatives in high efficiency with good diastereoselectivities and enantioselectivities (up to 92% yield, 20:1 dr, 99% ee). Moreover, complex substrates derived from natural products (bearing different functionalities) could be well-tolerated in the catalytic asymmetric cycloaddition. The mild reaction conditions, in conjunction with a broad substrate scope (44 examples), and a high level of stereoselectivity, provide great potential to build complex azocine compounds from simple building blocks.

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Asymmetric cycloaddition reaction has emerged as one of the powful and reliable strategies for the construction of enantioenriched molecules, especially those with polycyclic frameworks. Herein, we report the asymmetric decarboxylative...