A New Class of Ligands for Aqueous, Lanthanide-Catalyzed, Enantioselective Mukaiyama Aldol Reactions
摘要:
The development of aqueous methods for generating enantiopure beta-hydroxy carbonyl compounds is an important goal because these subunits compose many bioactive compounds and the ability to synthesize these groups in water has environmental and cost benefits. In this communication, we report a new class of ligands for aqueous, lanthanide-catalyzed, asymmetric Mukaiyama aldol reactions for the synthesis of chiral beta-hydroxy ketones. Furthermore, we have used luminescence-decay measurements to unveil mechanistic information regarding the catalytic reaction via changes in water-coordination number. The precatalysts presented here yielded beta-hydroxy carbonyls from aliphatic and aryl substrates with outstanding syn:anti ratios and enantiometric excesses of up to 49:1 and 97%, respectively.
A New Class of Ligands for Aqueous, Lanthanide-Catalyzed, Enantioselective Mukaiyama Aldol Reactions
作者:Yujiang Mei、Prabani Dissanayake、Matthew J. Allen
DOI:10.1021/ja107197p
日期:2010.9.22
The development of aqueous methods for generating enantiopure beta-hydroxy carbonyl compounds is an important goal because these subunits compose many bioactive compounds and the ability to synthesize these groups in water has environmental and cost benefits. In this communication, we report a new class of ligands for aqueous, lanthanide-catalyzed, asymmetric Mukaiyama aldol reactions for the synthesis of chiral beta-hydroxy ketones. Furthermore, we have used luminescence-decay measurements to unveil mechanistic information regarding the catalytic reaction via changes in water-coordination number. The precatalysts presented here yielded beta-hydroxy carbonyls from aliphatic and aryl substrates with outstanding syn:anti ratios and enantiometric excesses of up to 49:1 and 97%, respectively.
Study of the Lanthanide-Catalyzed, Aqueous, Asymmetric Mukaiyama Aldol Reaction
作者:Yujiang Mei、Derek J. Averill、Matthew J. Allen
DOI:10.1021/jo300800b
日期:2012.7.6
developed a new series of chiral lanthanide-containing complexes that produce Mukaiyama aldol products with outstanding enantioselectivities. In this paper, we describe an optimized ligand synthesis, trends in stereoselectivity that result from changing lanthanide ions, and an exploration of substrate scope that includes aromatic and aliphaticaldehydes and silyl enol ethers derived fromaromatic and aliphatic
Synthesis, Spectroscopic Characterization, and Reactivity of Water-Tolerant Eu<sup>3+</sup>-Based Precatalysts
作者:Derek J. Averill、Matthew J. Allen
DOI:10.1021/ic500790q
日期:2014.6.16
We report the synthesis, spectroscopic characterization, and reactivity of Eu3+ in the presence of a new set of chiral ligands designed for the aqueous, enantioselective Mukaiyama aldolreaction. Luminescence and NMR measurements were used to characterize the coordination environments of the Eu3+-based precatalysts, and this data is compared with yields and stereoselectivities. In addition to structure–function