Difluorination at Boron Leads to the First Electrophilic Ligated Boryl Radical (NHC-BF2. ).
Angew Chem Int Ed Engl
; 57(32): 10251-10256, 2018 Aug 06.
Article
em En
| MEDLINE
| ID: mdl-29928777
ABSTRACT
1,3-Dimethylimidazol-2-ylidene difluoroborane (NHC-BF2 H) was prepared in a one-pot, two-step reaction from the parent ligated borane (NHC-BH3 ). The derived difluoroboryl radical (NHC-BF2. ) was generated by laser flash photolysis experiments and characterized by UVâ
spectroscopy and rate-constant measurements. It is transient and reacts quickly with O2 . Unusually, it also reacts more rapidly with ethyl vinyl ether than with methyl acrylate. By this measure, it is the first electrophilic ligated boryl radical. Both NHC-BH3 and NHC-BF2 H serve as co-initiators in bulk photopolymerizations, converting both electron-poor and electron-rich monomers at roughly similar rates. However, the difluorinated coinitiator provides polymers with dramatically increased chain lengths from both monomers.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2018
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Article