Substituted propargyl acetates are converted into 4‐boryl‐2(5
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A novel and highly diastereoselective NBS-mediated cyclization of
- Award ID(s):
- 2102462
- NSF-PAR ID:
- 10537041
- Publisher / Repository:
- Royal Chemical Society
- Date Published:
- Journal Name:
- Chemical Science
- Edition / Version:
- Advance Article
- ISSN:
- 2041-6520
- Subject(s) / Keyword(s):
- beta lactams silyl imino ether NBS
- Format(s):
- Medium: X Other: PDF
- Sponsoring Org:
- National Science Foundation
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Abstract H )‐furanones upon thermolysis in the presence of an N‐heterocyclic carbene borane (NHC‐borane) and di‐tert ‐butyl peroxide. The acetyl methyl group is lost during the reaction as methane. Evidence suggests that the reaction proceeds by a sequence of radical events including: 1) addition of an NHC‐boryl radical to the triple bond; 2) cyclization of the resultant β‐borylalkenyl radical to the ester carbonyl group; 3) β‐scission of the so‐formed alkoxy radical to provide the 4‐boryl‐2(5H )‐furanone and a methyl radical; and 4) hydrogen abstraction from the NHC‐borane to return the initial NHC‐boryl radical and methane. -
Abstract Substituted propargyl acetates are converted into 4‐boryl‐2(5
H )‐furanones upon thermolysis in the presence of an N‐heterocyclic carbene borane (NHC‐borane) and di‐tert ‐butyl peroxide. The acetyl methyl group is lost during the reaction as methane. Evidence suggests that the reaction proceeds by a sequence of radical events including: 1) addition of an NHC‐boryl radical to the triple bond; 2) cyclization of the resultant β‐borylalkenyl radical to the ester carbonyl group; 3) β‐scission of the so‐formed alkoxy radical to provide the 4‐boryl‐2(5H )‐furanone and a methyl radical; and 4) hydrogen abstraction from the NHC‐borane to return the initial NHC‐boryl radical and methane. -
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