Substituent effects on the13C NMR spectra of ethylcis- andtrans-2-(p-substituted-phenyl)-1-cyclopanecarboxylates
作者:Yoshiaki Kusuyama、Kenjiro Tokami
DOI:10.1002/mrc.1260300415
日期:1992.4
13C NMR spectra were measured for a series of ethyl cis- and trans-2-(p-substituted - phenyl) - 1 - cyclopropanecarboxylates. The effects of the para substituents and the geometry on the chemical shifts are discussed.
One-pot approach for the synthesis of trans-cyclopropyl compounds from aldehydes. Application to the synthesis of GPR40 receptor agonists
作者:Michaël Davi、Hélène Lebel
DOI:10.1039/b810708d
日期:——
A novel multicatalytic one-pot process providing trans-cyclopropyl compounds from corresponding aldehydes has been developed and applied to the synthesis of GPR40 small molecule agonists.
[EN] MYOGLOBIN-BASED CATALYSTS FOR CARBENE TRANSFER REACTIONS<br/>[FR] CATALYSEURS À BASE DE MYOGLOBINE POUR RÉACTIONS DE TRANSFERT DE CARBÈNE
申请人:UNIV ROCHESTER
公开号:WO2016086015A1
公开(公告)日:2016-06-02
Methods are provided for carrying out carbene transfer transformations such as olefin cyclopropanation reactions, carbene heteroatom-H insertion reactions (heteroatom = N, S, Si), sigmatropic rearrangement reactions, and aldehyde olefination reactions with high efficiency and selectivity by using a novel class of myoglobin-based biocatalysts. These methods are useful for the synthesis of a variety of organic compounds which contain one or more new carbon-carbon or carbon-heteroatom (N, S, or Si) bond. The methods can be applied for conducting these transformations in vitro (i.e., using the biocatalyst in isolated form) and in vivo (i.e., using the biocatalyst in a whole cell system).
addition of the very reactive metallacarbene intermediate in an early transition state to the substrate alkene is concerted but strongly asynchronous, with substantial cationic character on one alkene carbon in the neighborhood of the transition state. Evidence from isotope effects and Hammett studies supports the nature of the transition state. Formation of a metallacyclobutaneintermediate by a [2+2] addition
Cyclopropanation of Olefins with Diazo Compounds Catalyzed by a Dicopper-substituted Silicotungstate [γ-H<sub>2</sub>SiW<sub>10</sub>O<sub>36</sub>Cu<sub>2</sub>(μ-1,1-N<sub>3</sub>)<sub>2</sub>]<sup>4−</sup>
作者:Keigo Kamata、Toshihiro Kimura、Noritaka Mizuno
DOI:10.1246/cl.2010.702
日期:2010.7.5
silicotungstate (TBA) 4 -[γ-H 2 SiW 10 O 36 Cu II 2 (μ-1,1-N 3 ) 2 ] (I, TBA = tetra-n-butylammonium) could act as an efficient precatalyst for the chemoselective cylopropanation of olefins with diazo compounds. Various kinds of olefins were efficiently converted to the corresponding cyclopropane derivatives in good yields.
双铜取代的 γ-Keggin 硅钨酸盐 (TBA) 4 -[γ-H 2 SiW 10 O 36 Cu II 2 (μ-1,1-N 3 ) 2 ] (I, TBA = 四正丁基铵)作为烯烃与重氮化合物化学选择性环丙烷化的有效预催化剂。各种烯烃以良好的收率有效地转化为相应的环丙烷衍生物。