Efficient Propargylation of Aldehydes and Ketones Catalyzed by Titanocene(III)
作者:José Justicia、Iris Sancho-Sanz、Enrique Álvarez-Manzaneda、J. Enrique Oltra、Juan M. Cuerva
DOI:10.1002/adsc.200900479
日期:2009.10
We describe a novel method for the propargylation of a wide range of aldehydes and ketonescatalyzed by titanocene(III) complexes under mild reaction conditions and compatible with many functional groups. Homopropargylic alcohols are obtained as the sole products even when ketones are used as starting materials, which is unusual in Barbier-type propargylations.
Gold(I)-Catalyzed [4+2] Annelation/Nucleophilic Addition Sequence: Stereoselective Synthesis of Functionalized Bicyclo[4.3.0]nonenes
作者:Sebastian Böhringer、Fabien Gagosz
DOI:10.1002/adsc.200800413
日期:2008.11.3
The gold(I)-catalyzed isomerization of readily available 1,8-dien-4-ynes allows the rapid construction of a variety of synthetically useful bicyclo[4.3.0]nonenes by a stereoselectivesequence involving a [4+2] annelation/nucleophilicaddition process.
The firstexample of lead-promoted “Barbier-type” (in situ Grignard) reaction has been demonstrated by the reaction of propargyl bromide with aldehydes in a Pb/Bu4NBr/Me3SiCl/DMF system.
intramolecular gold(I)-catalyzed [2+2+2] cycloaddition of oxo-1,5-enynes bearing protected homopropargylic alcohols provides access to oxatricyclic adducts with good to excellent diastereoselectivity. The intramolecular gold(I)-catalyzed [2+2+2] cycloaddition of oxo-1,5-enynes bearing protected homopropargylic alcohols provides access to oxatricyclic adducts with good to excellent diastereoselectivity.
Spiroketal Formation by Cascade Oxidative Dearomatization: An Approach to the Phorbaketal Skeleton
作者:Harry J. Shirley、Christopher D. Bray
DOI:10.1002/ejoc.201501370
日期:2016.3
Addition of PhI(OAc)2 to phenols that have meta-linked hydroxy ketones results in cascadeoxidativedearomatizing spirocyclization to give tricyclic spiroketals. This framework is found in the phorbaketal family of natural products.