Σ- versus π-activation of alkynyl benzoates using B(C₆F₅)₃

Molecules : a Journal of Synthetic Chemistry and Natural Product Chemistry
Alexander BährRebecca L Melen

Abstract

We have prepared a range of alkynyl benzoates in high yields and have investigated their reactivities with the strong Lewis acid B(C6F5)3. In such molecules both σ-activation of the carbonyl and π-activation of the alkyne are possible. In contrast to the reactivity of propargyl esters with B(C6F5)3 which proceed via 1,2-addition of the ester and B(C6F5)3 across the alkyne, the inclusion of an additional CH2 spacer switches off the intramolecular cyclization and selective σ-activation of the carbonyl group is observed through adduct formation. This change in reactivity appears due to the instability of the species which would be formed through B(C6F5)3 activation of the alkyne.

References

Oct 25, 2001·The Journal of Organic Chemistry·James M. BlackwellWarren E. Piers
May 24, 2005·Dalton Transactions : an International Journal of Inorganic Chemistry·Gerhard Erker
May 26, 2007·Angewandte Chemie·Jenny S J McCahillDouglas W Stephan
Apr 19, 2008·Organic & Biomolecular Chemistry·Douglas W Stephan
May 8, 2009·Dalton Transactions : an International Journal of Inorganic Chemistry·Douglas W Stephan
Jun 3, 2009·Journal of the American Chemical Society·Meghan A Dureen, Douglas W Stephan
Dec 22, 2009·Angewandte Chemie·Douglas W Stephan, Gerhard Erker
Apr 9, 2010·Chemical Communications : Chem Comm·Chao ChenGerhard Erker
Sep 14, 2010·Journal of the American Chemical Society·Chao ChenGerhard Erker
Oct 23, 2010·Chemical Communications : Chem Comm·Douglas W Stephan
May 27, 2011·Inorganic Chemistry·Warren E PiersLauren G Mercier
Nov 26, 2011·Chemical Communications : Chem Comm·Gerald Kehr, Gerhard Erker
Jan 14, 2012·Angewandte Chemie·Juri MöbusGerhard Erker
Apr 17, 2012·Organic & Biomolecular Chemistry·Douglas W Stephan
Jun 13, 2012·Dalton Transactions : an International Journal of Inorganic Chemistry·Daniel WinkelhausNorbert W Mitzel
Aug 8, 2013·Chemistry : a European Journal·Rebecca L MelenDouglas W Stephan
Dec 21, 2013·Journal of the American Chemical Society·Max M HansmannDouglas W Stephan
May 13, 2014·Chemical Communications : Chem Comm·Max M HansmannDouglas W Stephan
Dec 24, 2014·Accounts of Chemical Research·Douglas W Stephan

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Citations

May 31, 2016·Angewandte Chemie·Soumen SinhababuSelvarajan Nagendran
Aug 4, 2016·Angewandte Chemie·Lewis C WilkinsRebecca L Melen

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Methods Mentioned

BETA
NMR
X-ray
column chromatography

Software Mentioned

CrysalisPro
PLATON
SQUEEZE
SHELXTL

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