Arene extrusion as an approach to reductive elimination at boron: implication of carbene-ligated haloborylene as a transient reactive intermediate
Name
d4sc05524a.pdf
Description
Published version
Size
1.49 MB
Format
Adobe PDF
Checksum (MD5)
5871147ac86d5d4563a26ebfbfade220
Author(s)
Zhang, Chonghe
Gilliard, Robert J
Cummins, Christopher C
Date Issued
October 3, 2024
Journal
Chemical Science
Publisher
Royal Society of Chemistry
Citation
Zhang, Chonghe, Gilliard, Robert J and Cummins, Christopher C. 2024. "Arene extrusion as an approach to reductive elimination at boron: implication of carbene-ligated haloborylene as a transient reactive intermediate." Chemical Science, 15 (43).
Version
Final published version
Abstract
Herein, we report boron-centered arene extrusion reactions to afford putative cyclic(alkyl)(amino) carbene (CAAC)-ligated chloroborylene and bromoborylene intermediates. The borylene precursors, chloro-boranorbornadiene (ClB(C6Me6), 2Cl) and bromo-boranorbornadiene (BrB(C6Me6), 2Br) were synthesized through the reaction of the corresponding 1-halo-2,3,4,5-tetramethylborole dimer (XBC4Me4)2 (X = Cl, 1Cl; X = Br, 1Br) with 2-butyne. Treatment of 2Cl with CAACs resulted in the release of di-coordinate chloro-borylene (CAAC)BCl from hexamethylbenzene (C6Me6) at room temperature. In contrast, the reaction of 2Br with CAAC led to the formation of a boronium species [(CAAC)BC6Me6]+Br− (7) at room temperature. Heating 7 in toluene promoted the release of di-coordinate bromo-borylene (CAAC)BBr as a transient species. Surprisingly, heating 7 in dichloromethane resulted in the C–H activation of hexamethylbenzene. The conversion of a CAAC-stabilized bromo-borepin to a borylene, a boron-centered retro Büchner reaction, was also investigated.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1039/D4SC05524A
