Steric and electronic limitations for the Dötz benzannulation of aromatic alkynes

CuBr-mediated synthesis of 1,4-naphthoquinones via ring expansion of 2-aryl-1,3-indandiones

A CuBr-mediated direct insertion of alkenes into unstrained ring 2-aryl-1,3-indandiones is reported, which provides a one-carbon ring expansion strategy for the synthesis of 1,4-naphthoquinones. Entirely differing from the existing reports, the alkenes herein behave as C1 units to participate in annulation reactions. This transformation provides a facile route to access a class of highly functionalized 1,4-naphthoquinones with good yields, good functional-group tolerance and high atom-economy. Further research on the application of this reaction is currently underway in our laboratory.

Monoalkylation of aniline with trichloroacetimidate catalyzed by (±)-camphorsulfonic acid through an SN1 reaction based on dual hydrogen-bonding activation modes

Herein, the monoalkylation of anilines with trichloroacetimidates catalyzed by CSA was investigated theoretically, and it was found that the reaction occurred through an S_N1 reaction involving the dual hydrogen-bonding activation modes.

Reaction of Zirconacyclopentadienes with Ethynylferrocenes

Various zirconacyclopentadienes fully substituted at the metallacycle react with ethynylferrocene in the presence of [NiBr2(PPh3)2] or with methyl or ethyl 3-ferrocenylpropynoates in the presence of CuCl to give penta- and hexasubstituted phenylferrocenes, respectively. X-Ray diffraction analysis showed that the cyclopentadienyl and benzene rings in (5,8-diphenyl-1,2,3,4-tetrahydronapthalen-6-yl)ferrocene are rotated by as much as 51°.