We report a base-promoted cyclization of indene-dienes toward diverse spirocyclic indene scaffolds including hexacyclic spiroindenes bearing benzo pyran motifs and pentacyclic spiroindenes containing oxindole units in high yields with excellent diastereoselectivities.
A Co(III)-catalyzed C–H functionalization/spiroannulation of 1,3-indandione with alkenes has been developed for the synthesis of spiroindenes. This efficient protocol features excellent functional group tolerance and high atom- and step-economy.
The silylative-cyclization desymmetrization of 1,6-diynes has been realized. This reaction enabled the construction of silyl-functionalized spirocyclic oxindoles, indanone, quinolinone, and tetralone derivatives from readily available 1,6-diynes.
The design of new molecules from known structural motifs via [3 + 2] cycloaddition is a widely used strategy in modern drug discovery.
The recent advances of the visible-light-mediated photocatalytic cleavage of C–C and C–N bonds associated with amines and their derivatives, which featuring mild conditions, unique selectivity, broad substrate scope and green manner, are reviewed.