Steric buttressing in the Pauson–Khand reactions of aryl enynes
摘要:
A variety of aryl enynes have been constructed from o-iodophenol derivatives containing ortho-tert-butyl groups via O-alkylation and a Sonogashira cross-coupling reaction. These substrates undergo efficient thermal and oxidative intramolecular Pauson-Khand reactions leading to the formation of sterically congested cyclopentenones, as well as the formation of medium-sized rings, although in the latter case with unusual regioselectivity. Incorporation of a TMS moiety on the alkyne group in a higher homolog led to cyclization via the normal mode, albeit in relatively low yield. (c) 2007 Elsevier Ltd. All rights reserved.
Steric buttressing in the Pauson–Khand reactions of aryl enynes
摘要:
A variety of aryl enynes have been constructed from o-iodophenol derivatives containing ortho-tert-butyl groups via O-alkylation and a Sonogashira cross-coupling reaction. These substrates undergo efficient thermal and oxidative intramolecular Pauson-Khand reactions leading to the formation of sterically congested cyclopentenones, as well as the formation of medium-sized rings, although in the latter case with unusual regioselectivity. Incorporation of a TMS moiety on the alkyne group in a higher homolog led to cyclization via the normal mode, albeit in relatively low yield. (c) 2007 Elsevier Ltd. All rights reserved.
Steric buttressing in the Pauson–Khand reactions of aryl enynes
作者:Christian E. Madu、Hemalatha Seshadri、Carl J. Lovely
DOI:10.1016/j.tet.2007.03.131
日期:2007.6
A variety of aryl enynes have been constructed from o-iodophenol derivatives containing ortho-tert-butyl groups via O-alkylation and a Sonogashira cross-coupling reaction. These substrates undergo efficient thermal and oxidative intramolecular Pauson-Khand reactions leading to the formation of sterically congested cyclopentenones, as well as the formation of medium-sized rings, although in the latter case with unusual regioselectivity. Incorporation of a TMS moiety on the alkyne group in a higher homolog led to cyclization via the normal mode, albeit in relatively low yield. (c) 2007 Elsevier Ltd. All rights reserved.