67498-80-0Relevant academic research and scientific papers
Visible-Light Photocatalytic Intramolecular Cyclopropane Ring Expansion
Luis-Barrera, Javier,Laina-Martín, Víctor,Rigotti, Thomas,Peccati, Francesca,Solans-Monfort, Xavier,Sodupe, Mariona,Mas-Ballesté, Rubén,Liras, Marta,Alemán, José
, p. 7826 - 7830 (2017)
Described herein is a new visible-light photocatalytic strategy for the synthesis of enantioenriched dihydrofurans and cyclopentenes by an intramolecular nitro cyclopropane ring expansion reaction. Mechanistic studies and DFT calculations are used to elucidate the key factors in this new ring expansion reaction, and the need for the nitro group on the cyclopropane.
Biocatalytic Asymmetric Cyclopropanations via Enzyme-Bound Iminium Ion Intermediates
Kunzendorf, Andreas,Poelarends, Gerrit J.,Saifuddin, Mohammad,Saravanan, Thangavelu,Xu, Guangcai
supporting information, p. 24059 - 24063 (2021/10/07)
Cyclopropane rings are an important structural motif frequently found in many natural products and pharmaceuticals. Commonly, biocatalytic methodologies for the asymmetric synthesis of cyclopropanes rely on repurposed or artificial heme enzymes. Here, we engineered an unusual cofactor-independent cyclopropanation enzyme based on a promiscuous tautomerase for the enantioselective synthesis of various cyclopropanes via the nucleophilic addition of diethyl 2-chloromalonate to α,β-unsaturated aldehydes. The engineered enzyme promotes formation of the two new carbon-carbon bonds with excellent stereocontrol over both stereocenters, affording the desired cyclopropanes with high diastereo- and enantiopurity (d.r. up to 25:1; e.r. up to 99:1). Our results highlight the usefulness of promiscuous enzymes for expanding the biocatalytic repertoire for non-natural reactions.
KOH-promoted synthesis of oxirane functional derivatives from diethyl bromomalonate and aldehydes under phase-transfer catalysis conditions
Kryshtal, Galina V.,Zhdankina, Galina M.,Zlotin, Sergei G.
, p. 24 - 25 (2013/08/24)
The Darzens condensation of diethyl bromomalonate with aromatic or isoprenoid aldehydes under heterogeneous conditions (KOH/MeCN) in the presence of Bu4NPF6 as a recoverable phase-transfer catalyst afforded the corresponding diethyl 3-R-oxirane-2,2-dicarboxylates in high yields.
Obtention de cyclopropanes gem-dicarboxylate par cyclocondensation de carbanions bromo- et chloromalonate sur des accepteurs de Michael
Menn, Jean-Christophe Le,Tallec, Andre,Sarrazin, Jean
, p. 761 - 767 (2007/10/02)
Cyclopropane gem-dicarboxylates are prepared through cyclocondensation of chloro or bromomalonate carbanion and electrophilic alkenes.The carbanion can be formed in THF by deprotonation of the monohalomalonates with powdered potassium carbonate; the chlor
