Enantioselective Heck-Matsuda Arylations through Chiral Anion Phase-Transfer of Aryl Diazonium Salts
A mild, asymmetric Heck–Matsuda reaction of five-, six- and seven-membered ring alkenes and aryl diazonium salts is presented. High yields and enantioselectivities were achieved using Pd⁰ and chiral anion co-catalysts, the latter functioning as a chiral anion phase-transfer (CAPT) reagent. For certain substrate classes, the chiral anion catalysts were modulated to minimize the formation of undesired by-products. More specifically, BINAM-derived phosphoric acid catalysts were shown to prevent alkene isomerization in cyclopentene and cycloheptene starting materials. DFT(B3LYP-D3) computations revealed that increased product selectivity resulted from a chiral anion dependent lowering of the activation barrier for the desired pathway.
© 2017 Wiley-VCH. Issue Online: 08 May 2017. Version of Record online: 18 April 2017. Manuscript revised: 26 March 2017. Manuscript received: 26 February 2017. We acknowledge the National Institute of General Medical Sciences (R35 GM118190 to F.D.T. and R01 GM063540 to M.S.S.) for partial support of this work and IITB supercomputing for the computing time. C.M.A. thanks Science without Borders for a postdoctoral fellowship (CSF/CNPq 201758/2014-8) and H.M.N. acknowledges the UNCF and Merck for generous funding. We thank S. Kim for the paper revision and helpful discussion and suggestions, Dr. G. Schäfer for helpful suggestions, and Dr. W. Wolf and A. G. DiPasquale for the X-ray structure of 15 b and 19. X-ray crystallography was performed using the UC Berkeley College of Chemistry CheXray facility supported by the NIH Shared Instrumentation Grant S10-RR027172. The authors declare no conflict of interest.
Supplemental Material - anie201702107-sup-0001-misc_information.pdf
Accepted Version - nihms873719.pdf