Asymmetric Synthesis of Chiral Cyclopentanes Bearing an All-Carbon Quaternary Stereocenter by Zirconium-Catalyzed Double Carboalumination.

Herein, we report a zirconium-catalyzed enantio- and diastereoselective inter/intramolecular double carboalumination of unactivated 2-substituted 1,5-dienes, which provides efficient and direct access to chiral cyclopentanes through the generation of two stereocenters, including one all-carbon quaternary stereocenter, generally with excellent diastereo- and high enantioselectivity. This tandem carboalumination process creates two new C-C bonds as well as one C-Al bond, which can be oxidized in situ with O or hydrolyzed. Furthermore, the obtained chiral cyclopentanes can be readily functionalized to provide various chiral compounds.

One-Step Homologation for the Catalytic Asymmetric Synthesis of Deoxypropionates.

A one-step homologation protocol for the synthesis of natural products containing deoxypropionate motif is described by the combination of Zr-catalyzed asymmetric carboalumination of alkenes (ZACA)-Pd-catalyzed vinylation and ZACA-oxidation reaction. In contrast to most other synthetic strategies used to date that typically require three steps per deoxypropionate unit due to the functional-group interconversions, our one-step homologation strategy promises to provide a general and more efficient synthetic route toward deoxypropionate natural products as exemplified by significant improvements in the syntheses of intermediates and/or final products of mycolipenic acid 1 and its analogue 2, (-)-rasfonin, and syn- and anti-dicarboxylic acids 5 and 6.

Nickel-catalyzed C-H arylation of azoles with haloarenes: scope, mechanism, and applications to the synthesis of bioactive molecules.

Novel nickel-based catalytic systems for the C-H arylation of azoles with haloarenes and aryl triflates have been developed. We have established that Ni(OAc)(2)/bipy/LiOtBu serves as a general catalytic system for the coupling with aryl bromides and iodides as aryl electrophiles. For couplings with more challenging electrophiles, such as aryl chlorides and triflates, the Ni(OAc)(2)/dppf (dppf = 1,1'-bis(diphenylphosphino)ferrocene) system was found to be effective.