A neutral diradical based on corannulene with curved and nonalternant π conjugation has been synthesized and isolated as air‐stable crystals. Sizable spin delocalization and strong intramolecular exchange interaction in the intrinsically three‐dimensional π network (see picture), as well as significant diradical contributions in the ground state, were experimentally disclosed.
A palladium-catalyzed asymmetric annulative dearomatization of phenols with butene dicarbonate is reported, enabling twofold decarboxylativeallylation to regioselectively produce a range of spirocyclohexadienones with 29–95% yields and 74–99% ee. A catalytic dearomative formal [4 + 2] cyclization of 1,1′-biphenyl-2,4′-diols delivered spiro[chromane-4,1′-cyclohexane]-2′,5′-dien-4′-ones with high enantioselectivity