Mizoroki–Heck Cyclizations of Amide Derivatives for the Introduction of Quaternary Centers
作者:Jose M. Medina、Jesus Moreno、Sophie Racine、Shuaijing Du、Neil K. Garg
DOI:10.1002/anie.201703174
日期:2017.6
report non-decarbonylative Mizoroki–Heck reactions of amide derivatives. The transformation relies on the use of nickel catalysis and proceeds using sterically hindered tri- and tetrasubstituted olefins to give products containing quaternary centers. The resulting polycyclic or spirocyclic products can be obtained in good yields. Moreover, a diastereoselective variant of this method gives access to an
A new and single-step method for the synthesis of trisubstituted α,β-unsaturated esters using the lithium enolates of S-1-ethoxycarbonylethyl diethyl phosphorothioate (Ib) and S-1-ethoxycarbonylbutyl diethyl phosphorothioate (Ic) has been developed.
Regio- and Stereoselectivity of Water Elimination as a Function of Ring Size
作者:Björn Greve、Peter Imming
DOI:10.1021/jo970989g
日期:1997.11.1
The elimination of water from tertiary alcohols was studied for carbocycles of ringsize 5-16. The resulting olefins 3-5 were discriminated by NMR spectroscopy. The relative amount of their formation reflects the steric idiosyncrasies of the respective ring systems. The behavior of the medium-sized rings yielded experimental proof to the I-strain concept.