Polystyrenes with chiral phosphoramide substituents as Lewis base catalysts for asymmetric addition of allyltrichlorosilane: enhancement of catalytic performance by polymer effect.
ABSTRACT In the asymmetric addition of allyltrichlorosilane to benzaldehyde, polystyrenes with chiral phosphoramide substituents as Lewis base catalysts showed up to 2.4 times better catalytic activity and 1.4 times higher enantioselectivity than the corresponding low-molecular-weight analogues.
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Article: Asymmetric organocatalysis[Show abstract] [Hide abstract]
ABSTRACT: This review is intended to update the impressive amount of recent developments of asymmetric organocatalysis in numerous reaction types, such as nucleophilic additions to electron-deficient CC double bonds, nucleophilic additions to CO double bonds, nucleophilic additions to CN double bonds, nucleophilic additions to unsaturated nitrogen, nucleophilic substitutions at aliphatic carbon, cycloaddition reactions, oxidations, reductions, kinetic resolutions and miscellaneous reactions, covering the literature from 2005 to 2007. This review clearly demonstrates the explosive growth and power of this new field of organic chemistry, which has become, in the last few years, the third methodology of asymmetric catalysis besides organometallic and enzymatic catalysis.Figure optionsView in workspaceDownload full-size imageDownload as PowerPoint slideChemInform 09/2007; 63(38):9267–9331.
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ABSTRACT: In the last few years the possibility of effectively employing relatively simple organic molecules as enantioselective catalysts able to promote reactions with high levels of chemical efficiency and stereocontrol has been demonstrated. In this context chiral Lewis bases play an important role as promoters of a large variety of stereoselective reactions. In the field of silicon-based chemistry several, new metal-free compounds have recently been developed to efficiently catalyze different reactions where “hypervalent” silicates are involved as intermediates. The review will present the more recent achievements in silicate-mediated stereoselective reactions catalyzed by chiral Lewis bases.Coordination Chemistry Reviews 03/2008; · 12.10 Impact Factor
- Catalytic Methods in Asymmetric Synthesis: Advanced Materials, Techniques, and Applications, 07/2011: pages 83 - 175; , ISBN: 9781118087992