5-endo cyclizations of NHC-boraallyl radicals bearing ester substituents : characterization of derived 1,2-oxaborole radicals and boralactones
Date
21/11/2018Metadata
Show full item recordAbstract
EPR studies of radical hydrogen abstraction reactions of N-heterocyclic carbene (NHC) complexes of alkenylboranes bearing two ester substituents revealed not the expected boraallyl radicals but instead isomeric 1,2-oaxborole radicals. Such radicals are new, and DFT calculations show that they arise from the initially formed boraallyl radicals by a rapid, exothermic 5-endo cyclization. These spectroscopic and computational discoveries prompted a series of preparative experiments that provided access to a novel family of robust NHC-boralactones. A one-pot procedure was developed to access the boralactones directly from an NHC-borane (NHC-BH3) and dimethyl acetylenedicarboxylate.
Citation
Dai , W , McFadden , T R , Curran , D P , Früchtl , H A & Walton , J C 2018 , ' 5- endo cyclizations of NHC-boraallyl radicals bearing ester substituents : characterization of derived 1,2-oxaborole radicals and boralactones ' , Journal of the American Chemical Society , vol. 140 , no. 46 , pp. 15868-15875 . https://doi.org/10.1021/jacs.8b09288
Publication
Journal of the American Chemical Society
Status
Peer reviewed
ISSN
0002-7863Type
Journal article
Description
J.C.W. thanks EaStCHEM for financial support, and D.P.C. thanks the U.S. National Science Foundation. Computational support was provided through the EaStCHEM Research Computing Facility.Collections
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