A formal 1,6-conjugated addition-mediated [4 + 1] annulation of ortho-hydroxyphenyl-substituted para-quinone methides with sulfonium or ammonium bromides has been described. This domino-type process offered an efficient method for the synthesis of 2,3-dihydrobenzofurans in good yields, exhibiting good functional group tolerance, scalability and high diastereoselectivity.

Transition-metal-catalyzed tandem Heck/carbonylation reaction has emerged as a powerful tool for the synthesis of structurally diverse carbonyl molecules, as well as natural products and pharmaceuticals. However, the asymmetric version was rarely reported, and remains a challenging topic. Herein, we describe a palladium-catalyzed asymmetric tandem Heck/carbonylation desymmetrization of cyclopentenes. Alcohols, phenols and amines are employed as versatile coupling reagents for the construction of multifunctional chiral bicyclo[3.2.1]octanes with one all-carbon quaternary and two tertiary carbon stereogenic centers in high diastereo- and enantioselectivities. This study represents an important progress in both the asymmetric tandem Heck/carbonylation reactions and enantioselective difunctionalization of internal alkenes.