Borylative cyclisation of diynes using BCl3 and borocations

The borylative cyclisation of 1,2-dialkynyl benzenes with BCl3 leads to dibenzopentalenes (via intramolecular SEAr) or benzofulvenes (via chloride addition) depending on substituents, with stabilised vinyl cation intermediates (e.g. with a p-MeO-C6H4-group) favouring the latter. The use of borocatio...

Full description

Saved in:
Bibliographic Details
Published in:Organic & biomolecular chemistry 2019, Vol.17 (22), p.5520-5525
Main Authors: Warner, Andrew J, Enright, Kieron M, Cole, John M, Kang, Yuan, McGough, John S, Ingleson, Michael J
Format: Article
Language:English
Subjects:
Boron chlorides
Cartesian coordinates
Crystallography
Intermediates
NMR
Nuclear magnetic resonance
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The borylative cyclisation of 1,2-dialkynyl benzenes with BCl3 leads to dibenzopentalenes (via intramolecular SEAr) or benzofulvenes (via chloride addition) depending on substituents, with stabilised vinyl cation intermediates (e.g. with a p-MeO-C6H4-group) favouring the latter. The use of borocations leads to more selective dibenzopentalene formation, while other diyne frameworks undergo intramolecular SEAr selectively even with p-MeO groups.
ISSN:1477-0520
1477-0539
DOI:10.1039/c9ob00991d