Acid-catalyzed Asymmetric Reaction Research Articles

Chiral Brønsted Acid-Catalyzed Asymmetric Reaction via Vinylidene Ortho-Quinone Methides.

Vinylidene ortho-quinone methides (VQMs) have been proven to be versatile and crucial intermediates in the catalytic asymmetric reaction in last decade, and thus have drawn considerable concentrations on account of the practical application in the construction of enantiomerically pure functional organic molecules. However, in comparison to the well established chiral Brønsted base-catalyzed asymmetric reaction via VQMs, chiral Brønsted acid-catalyzed reaction is rarely studied and there is no systematic summary to date. In this review, we summarize the recent advances in the chiral Brønsted acid-catalyzed asymmetric reaction via VQMs according to three types of reactions: a) intermolecular asymmetric nucleophilic addition to VQMs; b) intermolecular asymmetric cycloaddition of VQMs; c) intramolecular asymmetric cyclization of VQMs. Finally, we put forward the remained challenges and opportunities for potential breakthroughs in this area.

Concise synthesis of binaphthol-derived chiral dicarboxylic acids

3,3′-Disubstituted 1,1′-binaphthyl-2,2′-dicarboxylic acids (1) were synthesized in three or four steps from commercially available BINOL via carbon dioxide fixation with organolithium to incorporate the carboxylic acid moieties, followed by either carboxylate-directed ortho-C–H arylation or Suzuki cross-coupling. This method provides easy access to various types of axiially chiral dicarboxylic acids, which should be useful for studies of chiral Brønsted acid-catalyzed asymmetric reactions.