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Title: The Thermal Rearrangement of an NHC‐Ligated 3‐Benzoborepin to an NHC‐Boranorcaradiene
Abstract

An N‐heterocyclic‐carbene‐ligated 3‐benzoborepin with a bridged structure has been synthesized by double radicaltrans‐hydroboration of benzo[3,4]cycloundec‐3‐ene‐1,5‐diyne with an N‐heterocyclic carbene borane. The thermal reaction of the NHC‐ligated borepin at 150 °C gives an isolable NHC‐boranorcaradiene. Experiments and density functional theory calculations support a mechanism whereby the borepin initially rearranges to a boranorcaradiene by a thermal 6π‐electrocyclic reaction. This is followed by 1,5‐boron shift to give a rearranged boranorcaradiene. This shift occurs with stereoinversion at boron through a transition state with open‐shell diradical character. This is the first example of the isolation of a boranorcaradiene from a thermal reaction of a borepin.

 
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Award ID(s):
1654122
NSF-PAR ID:
10124858
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Angewandte Chemie
Volume:
132
Issue:
2
ISSN:
0044-8249
Page Range / eLocation ID:
p. 913-919
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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