lariat ethers have been synthesized. These macrocycles and their derivatives proved to be efficient catalysts in the cyclopropanation of (E)-3-phenyl-2-(phenylsulfonyl)acrylonitrile performed with diethyl bromomalonate under mild phase transfer conditions. Among the catalysts tested, the macrocycle having methylα-d-galactopyranoside unit generated the highest asymmetric induction (80% ee). In the
Asymmetric cyclopropanation of conjugated cyanosulfones using a novel cupreine organocatalyst: rapid access to δ<sup>3</sup>-amino acids
作者:Lewis S. Aitken、Lisa E. Hammond、Rajkumar Sundaram、Kenneth Shankland、Geoffrey D. Brown、Alexander J. A. Cobb
DOI:10.1039/c5cc05158d
日期:——
A novel hydroquinine derived organocatalyst has been used to make cyclopropanes useful in the construction of δ3-amino acids.
一种新型的羟基喹啉衍生有机催化剂已被用于制备环丙烷,用于构建δ3-氨基酸。
Solid catalysts for the production of fine chemicals: the use of natural phosphate alone and doped base catalysts for the synthesis of unsaturated arylsulfones
作者:Mohamed Zahouily、Mohamed Salah、Bouchaib Bahlaouane、Ahmed Rayadh、Abdelaziz Houmam、Emad A Hamed、Saı̈d Sebti
DOI:10.1016/j.tet.2003.11.086
日期:2004.2
The inexpensive natural phosphate, both alone and doped with potassium fluoride, is a new basic catalyst for the synthesis of α,β-unsaturated arylsulfones. Activation by water and benzyltriethylammonium chloride has also been investigated. When using an ammonium salt, natural phosphate doped with potassium fluoride is an excellent solid support for the synthesis of α,β-unsaturated arylsulfones, leading
Joined together, organocatalysts aldehydes and sulfones: A diaryl prolinol silyl ether was found to catalyse efficiently and enantioselectively the conjugate addition of aldehydes to vinyl sulfones (see scheme). The ample synthetic utility of the resulting adducts is illustrated.