Cooperative Catalysis With Block Copolymer Micelles: A Combinatorial Approach
摘要:
A rapid approach to identifying complementary catalytic groups using combinations of functional polymers is presented. Amphiphilic polymers with "clickable" hydrophobic blocks were used to create a library of functional polymers, each bearing a single functionality. The polymers were combined in water, yielding mixed micelles. As the functional groups were colocalized in the hydrophobic microphase, they could act cooperatively, giving rise to new modes of catalysis. The multipolymer "clumps" were screened for catalytic activity, both in the presence and absence of metal ions. A number of catalyst candidates were identified across a wide range of model reaction types. One of the catalytic systems discovered was used to perform a number of preparative-scale syntheses. Our approach provides easy access to a range of enzyme-inspired cooperative catalysts.
Ligand effects in aluminium-catalyzed asymmetric Baeyer–Villiger reactions
作者:Jean-Cédric Frison、Chiara Palazzi、Carsten Bolm
DOI:10.1016/j.tet.2005.12.080
日期:2006.7
AsymmetricBaeyer–Villigeroxidations of racemic and prochiral cyclobutanones can be performed with chiral aluminium-based Lewis acids resulting in products with good enantioselectivities in high yields. By employing substituted BINOL derivatives as ligands, remarkable catalyst efficiencies have been achieved and γ-butyrolactones with up to 84% ee were obtained. The relation between the electronic
A chiral metallacyclophane for asymmetric catalysisElectonic supplementary information (ESI) available: experimental details and analytical data for 2 and 3, and general procedure for analysis. See http://www.rsc.org/suppdata/cc/b2/b208324h/
作者:Hua Jiang、Aiguo Hu、Wenbin Lin
DOI:10.1039/b208324h
日期:2003.12.19
Chiral metallacyclophanes were self-assembled from cis-(PEt3)2PtCl2 and enantiopure atropisomeric 1,1′-binaphthyl-6,6′-bis(acetylenes) and used in highly enantioselective catalytic diethylzinc additions to aldehydes to afford chiral secondary alcohols.
Quinoid BINOL-type compounds as a novel class of chiral ligands
作者:Ana Minatti、Karl Heinz Dötz
DOI:10.1016/j.tetasy.2005.08.026
日期:2005.10
A short and efficient synthesis of a novel family of quinone-substituted BINOL-type ligands exploiting the chromium-templated [3+2+1]benzannulationreaction as the key step is reported.
Synthesis of novel non-centrosymmetric crystalline materials for quadratic non-linear optics
作者:Man Shing Wong、Jean-Fran�ois Nicoud
DOI:10.1039/c39940000249
日期:——
Racemic 6,6′-bis-(phenylethynyl)-1,1′-binaphthyls and five of the six 6,4′-disubstituted 2-napthylpehenylacetylenes designed and synthesized show non-linear optical (NLO) activity in the Kurtz and Perry second-harmonic generation (SHG) powder test.