Diastereoselective sulfa-Michael reactions controlled by a biomass-derived chiral auxiliary
作者:Julian Klepp、Harald Podversnik、Johannes Puschnig、Andrew Wallace、Ben W. Greatrex
DOI:10.1016/j.tet.2019.05.051
日期:2019.7
A family of chiralauxiliaries derived from the lignocellulosic biomass pyrolysis product levoglucosenone (LGO) has been screened in the sulfa-Michael reaction. When promoted by inorganic bases with potassium counterions, the auxiliary with geminal benzyl substituents showed diastereoselectivity up to 90:10 for a broad range of α,β-unsaturated esters.
[EN] CHIRAL AUXILIARIES AND USES THEREOF<br/>[FR] AUXILIAIRES CHIRAUX ET LEURS UTILISATIONS
申请人:UNIV OF NEW ENGLAND
公开号:WO2019060953A1
公开(公告)日:2019-04-04
The present invention relates to chiral auxiliaries and the syntheses thereof and uses thereof.
本发明涉及手性辅助剂及其合成和用途。
Desymmetrization and Kinetic Resolution of Endoperoxides Using a Bifunctional Organocatalyst
作者:Sarah V. A.-M. Legendre、Christopher J. Sumby、Amir Karton、Ben W. Greatrex
DOI:10.1021/acs.joc.3c00278
日期:2023.8.18
Bifunctional thiourea/amine organocatalysts have been used for the desymmetrization of meso-endoperoxides using the Kornblum–DeLaMare reaction, giving 4-hydroxyketones in 78–98% yields with ≤98:2 enantioselectivity. The influence of the catalyst structure, solvent, and temperature was examined. The most promising catalyst was applied to the kinetic resolution of racemic endoperoxides to give enantioenriched
The present invention relates to chiral auxiliaries and the syntheses thereof and uses thereof.
本发明涉及手性助剂及其合成和用途。
Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions
作者:Martyn Jevric、Julian Klepp、Johannes Puschnig、Oscar Lamb、Christopher J Sumby、Ben W Greatrex
DOI:10.3762/bjoc.20.74
日期:——
Abstract A skeletal rearrangement of a series of 6,8-dioxabicyclo[3.2.1]octan-4-ols has been developed using SOCl2 in the presence of pyridine. An oxygen migration from C5 to C4 was observed when the C4 alcohols were treated with SOCl2/pyridine, giving a 2-chloro-3,8-dioxabicyclo[3.2.1]octane ring-system via the chlorosulfite intermediate. Analogous allylic alcohols with endocyclic and exocyclic unsaturations