A chiral organocatalytic polymer-based monolithic reactor
作者:Valerio Chiroli、Maurizio Benaglia、Alessandra Puglisi、Riccardo Porta、Ravindra P. Jumde、Alessandro Mandoli
DOI:10.1039/c4gc00031e
日期:——
properly modified enantiomericallypure imidazolidinone inside a stainless steel column in the presence of dodecanol and toluene as porogens afforded the first example of a chiral organocatalyst immobilized onto a monolithic reactor. Organocatalyzed cycloadditionsbetween cyclopentadiene and cinnamic aldehyde were performed under continuous-flow conditions; by optimizing the experimental set up, excellent
Highly Enantioselective Diels–Alder Reaction Catalyzed by Chiral Imidazolidinone
作者:Yongjiang Wang、Xiaoliang Xu、Wen Pei
DOI:10.1080/00397910802632571
日期:2009.5.7
Abstract New chiral imidazolidinone with an indole group was synthesized and used to catalyze the Diels–Alder reaction of α,β-unsaturated aldehyde with diene. High enantiomeric excesses and good yields were obtained. The reaction media were also surveyed. The best result in terms of enantioselectivity was achieved using acrolein and 2,3-dimethylbutdiene (up to 95% ee) in CH3OH/H2O.
(Mac‐SILC) in the pores of silica gel with the aid of an ionic liquid – 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide. The heterogenized organocatalyst was utilized for the enantioselectiveDiels–Alder reaction of cyclopentadiene and cinnamaldehyde, recovered by simple filtration and subsequent evacuation, and repeatedly used up to six times in 81% average chemical yield, 87% ee for endo‐
Poly(methylhydrosiloxane)-supported chiral imidazolinones: new versatile, highly efficient and recyclable organocatalysts for stereoselective Diels–Alder cycloaddition reactions
作者:Stefania Guizzetti、Maurizio Benaglia、Jay S. Siegel
DOI:10.1039/c2cc17919a
日期:——
supported organic catalysts promoted the Diels-Alder reaction of dienes with alpha,beta-unsaturated aldehydes, also in pure water, in yields and enantiomeric excesses comparable to those observed with the non-supported catalysts (up to 93% ee). Recycling of the catalysts was performed with no loss of enantioselectivity for at least five reaction cycles.
Incorporation of Functional Guest Molecules into an Internally Functionalizable Dendrimer through Olefin Metathesis
作者:Catherine O. Liang、Jean M. J. Fréchet
DOI:10.1021/ma050818a
日期:2005.7.26
A poly(aryl ether) dendrimer bearing 22 allyl groups throughout the interior of the molecule has been prepared using a convergent synthetic approach. The internalfunctionalities of this dendrimer can be used to attach small molecule guests to the interior of the dendrimer using olefin metathesis. A ruthenium-based Grubbs catalyst was used to covalently attach an allylated pyrene and imidazolidinone