Superparamagnetic Nanoparticle-Supported (S)-Diphenyl- prolinol Trimethylsilyl Ether as a Recyclable Catalyst for Asymmetric Michael Addition in Water
作者:Bang Gen Wang、Bao Chun Ma、Qiong Wang、Wei Wang
DOI:10.1002/adsc.201000508
日期:2010.11.22
A new superparamagneticnanoparticle-supported (S)-diphenylprolinol trimethylsilylether (Jørgensen–Hayashi catalyst) was synthesized and applied for the asymmetricMichaeladdition of aldehydes to nitroalkenes in water, which gives products in moderate to good yields (up to 96%), good enantioselectivity (up to 90% ee) and diastereoselectivities (up to 99:1). The immobilized catalyst could be easily
“Bottom-Up” Embedding of the Jørgensen-Hayashi Catalyst into a Chiral Porous Polymer for Highly Efficient Heterogeneous Asymmetric Organocatalysis
作者:Chang An Wang、Zhi Kun Zhang、Tao Yue、Ya Lei Sun、Lei Wang、Wei David Wang、Yuan Zhang、Chong Liu、Wei Wang
DOI:10.1002/chem.201200753
日期:2012.5.29
construction of a robust chiralporouspolymer (JH‐CPP) embedded with the Jørgensen–Hayashicatalyst (JH) has been successfully achieved for highlyefficientheterogeneousorganocatalysis. The high BET surface area, wide openings and interconnected nanopores of JH‐CPP increase the accessibility of catalytic sites and as such the catalyst shows excellent activity in catalyzing the asymmetric Michael addition
The asymmetric challenge! New camphor‐based prolinamides were designed, synthesized, and proven to be a highly efficient organocatalysts for asymmetricMichael reactions. Treatment of unmodified aldehydes with nitroalkenes in the presence of 5–10 mol % organocatalysts provided the desired Michael products in high chemical yields (up to 94 %) and high to excellent levels of diastereo‐ and enantioselectivities
A highly efficient access to enantiopure tetrahydropyridines: dual-organocatalyst-promoted asymmetric cascade reaction
作者:Hua Lin、Yu Tan、Wen-Jie Liu、Zhi-Cheng Zhang、Xing-Wen Sun、Guo-Qiang Lin
DOI:10.1039/c3cc40690c
日期:——
A highly efficient cascade process of Michael–aza-Henry–hemiaminalization–dehydration was established for the construction of enantiopure tetrahydropyridines using the combination of prolinol trimethylsilyl ether and cinchona alkaloid catalysts. This new approach allowed for the application of aliphatic imines, generated in situ from aldehydes and amines. Good yields (up to 90%), high enantio- (up to >99% ee) and diastereoselectivities (>99 : 1 d.r. in all cases) were achieved for a broad spectrum of substrates under mild conditions.
A versatile one‐step photopolymerization approach for the immobilization of enantioselectiveorganocatalysts is presented. Chiral organocatalyst‐containing monoliths based on polystyrene divinylbenzene copolymer were generated inside channels of microfluidic chips. Exemplary performance tests were performed for the monolithic Hayashi–Jørgensen catalyst in continuous flow, which showed good results