Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 27, 2018 | Supplemental Material + Accepted Version
Journal Article Open

Teaching an old carbocation new tricks: Intermolecular C–H insertion reactions of vinyl cations

Abstract

Vinyl carbocations have been the subject of extensive experimental and theoretical studies over the past five decades. Despite this long history in chemistry, the utility of vinyl cations in chemical synthesis has been limited, with most reactivity studies focusing on solvolysis reactions or intramolecular processes. Here we report synthetic and mechanistic studies of vinyl cations generated through silylium–weakly coordinating anion catalysis. We find that these reactive intermediates undergo mild intermolecular carbon-carbon bond–forming reactions, including carbon-hydrogen (C–H) insertion into unactivated sp³ C–H bonds and reductive Friedel-Crafts reactions with arenes. Moreover, we conducted computational studies of these alkane C–H functionalization reactions and discovered that they proceed through nonclassical, ambimodal transition structures. This reaction manifold provides a framework for the catalytic functionalization of hydrocarbons using simple ketone derivatives.

Additional Information

© 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works http://www.sciencemag.org/about/science-licenses-journal-article-reuseThis is an article distributed under the terms of the Science Journals Default License. Received for publication March 9, 2018. Accepted for publication June 5, 2018. H.M.N. thanks M. Jung for reagents and advice. Support was generously provided by the David and Lucile Packard Foundation (to H.M.N.), the Alfred P. Sloan Foundation (to H.M.N.), the National Science Foundation (CHE-1361104 to K.N.H.), and the National Natural Science Foundation of China (grant nos. 11504130, 51673164, and 21501169 to L.Z.). A.L.B. thanks the Christopher S. Foote Fellowship for funding. The authors thank the UCLA Molecular Instrumentation Center for NMR instrumentation, x-ray crystallography, and the Mass Spectrometry facility at the University of California, Irvine. Author contributions: S.P., B.S., and A.L.B. designed and conducted experiments. T.R.B., L.Z., and Z.Y. designed and conducted computations. H.M.N., K.N.H., S.P., B.S., A.L.B., and T.R.B. prepared the manuscript. The authors declare no competing financial interests. Data and materials availability: Crystallographic data are available free of charge from the Cambridge Crystallographic Data Centre under CCDC 1838441. Additional experimental procedures and characterization data are provided in the supplementary materials.

Attached Files

Accepted Version - nihms-1035919.pdf

Supplemental Material - aat5440_Popov_SM.pdf

Supplemental Material - aat5440s1.mp4

Supplemental Material - aat5440s2.mp4

Supplemental Material - aat5440s3.mp4

Supplemental Material - aat5440s4.mp4

Supplemental Material - aat5440s5.mp4

Files

aat5440_Popov_SM.pdf
Files (62.6 MB)
Name Size Download all
md5:794b38d8809d1c9a9868cde7455503cf
15.8 MB Preview Download
md5:526a5bda293929b79f6226528a54df91
8.3 MB Download
md5:215a8fe1fe86b77dd08aa0d6ee8c457a
6.2 MB Download
md5:1ade1554ca7ead155aff644aecc3d342
13.1 MB Download
md5:94eac3c733398ab0501c1143ee7cffd1
11.4 MB Download
md5:d4159a0d0bd727d74a1b336a2b956c4f
1.7 MB Preview Download
md5:78d5466c3322be3ce072d5f33ffad4cd
6.2 MB Download

Additional details

Created:
October 4, 2023
Modified:
October 24, 2023