Download PDF
Synfacts 2015; 11(1): 0035
DOI: 10.1055/s-0034-1379664
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart · New York

PB&J: Phosphorus and Boron at the Junction of Two π-Systems

Contributor(s):
Timothy M. Swager
,
Sibo Lin
Chen G.-Q, Kehr G, Daniliuc CG, Erker G * Universität Münster, Germany
1,1-Alkenylboration of Diarylphosphino-enynes: Convenient Synthetic Entry to Vicinal P/B Lewis Pairs at Extended Conjugated π-Frameworks.

Org. Biomol. Chem. 2015;
DOI: 10.1039/C4OB02134G
Search in Google Scholar
Further Information

Publication History

Publication Date:
15 December 2014 (online)

 
 PDF Download Permissions and Reprints

Key words

electrocyclization - ring closure - ring opening

Significance

The 1,1-alkenylboration of alkynes is an unique route to large conjugated π-systems. Erker and co-workers demonstrate that the 1,1-alkenylboration of diarylphosphino-enynes proceeds similarly to give hexatrienes 1. Upon thermolysis, two concurrent transformations occur: 6π-electrocyclic ring closure of the hexatriene ­moiety and nucleophilic aromatic substitution (SNAr) of a pentafluorophenyl group by the phosphine nucleophile to yield heterotricyclic products 2.


#

Comment

These reactions are a convenient synthetic route to new molecules containing vicinal P/B Lewis pairs. Thermolysis products are only reported for 1a and 1b. Would the thermolysis of 1c and 1d, which contain bulky (Mes)2P nucleophiles, result in electrocyclic ring closure without concurrent SNAr?


#
#


   Permissions and Reprints