Kulinkovich-type reactions of thioamides: similar to those of carboxylic amides?
作者:Ewelina Augustowska、Antoine Boiron、Jérôme Deffit、Yvan Six
DOI:10.1039/c2cc31394d
日期:——
The behaviour of thioamides under Kulinkovich-type conditions is compared with the known reactivity of carboxylic amides. Dramatic differences are disclosed.
A study of the reaction of n-BuLi with Ti(Oi-Pr)4 as a method to generate titanacyclopropane and titanacyclopropene species
作者:Valentin A. Rassadin、Yvan Six
DOI:10.1016/j.tet.2013.12.048
日期:2014.1
The use of the combination of reagents Ti(Oi-Pr)(4)/n-BuLi, introduced by the group of J.J. Eisch in 2001, has only found a few applications so far, with sometimes conflicting observations. This article describes a study aimed at clarifying the nature, the stability and the reactivity of the active organometallic species involved. Reactions with CO2 and other trapping reagents reveal that it is generated within a few minutes at 0 degrees C in THF, where it can be considered to be stable for 30 min. Most of our results are consistent with the expected titanacyclopropane nature of this reagent but some observations suggest that the chemistry at play may be more complicated. (C) 2013 Elsevier Ltd. All rights reserved.
Diastereoselective Ti-mediated preparation of bicyclic aminocyclopropanes from N-alkenyl amides
作者:Claire Madelaine、Andrea K. Buzas、Justyna A. Kowalska-Six、Yvan Six、Benoît Crousse
DOI:10.1016/j.tetlet.2009.07.031
日期:2009.9
Intramolecular Ti-mediated alkene-amide couplings of a range of N-alk-3-enyl amides fitted with a substituent at the homoallylic position are described. CF3-substituted compounds are suitable substrates and bicyclic aminocyclopropanes bearing a CF3 group can be prepared in this way. Good diastereoselectivities can be observed depending on the substitution pattern, and best results are obtained in diethyl ether rather than in THF. (C) 2009 Elsevier Ltd. All rights reserved.