A new organocatalytic enantioselective Michael addition of α-fluoromalonate to enals has been developed.The process is efficiently catalyzed by readily available chiral diphenylpyrolinol TES ether under mild reaction...A new organocatalytic enantioselective Michael addition of α-fluoromalonate to enals has been developed.The process is efficiently catalyzed by readily available chiral diphenylpyrolinol TES ether under mild reaction conditions to afford versatile highly enantioenriched fluorinated aldehydes.展开更多
Phthalimide derivatives as nitrogen nucleophiles with α,β-unsaturated aldehydes for asymmetric aza-Michael additions have been reported. The reactions proceed smoothly to afford corresponding Michael adducts in goo...Phthalimide derivatives as nitrogen nucleophiles with α,β-unsaturated aldehydes for asymmetric aza-Michael additions have been reported. The reactions proceed smoothly to afford corresponding Michael adducts in good yields （up to 98%） and enantioselectivities （up to 95% ee）.展开更多
A series of KF/Al2O3 catalyzed Michael-addition reactions between malononitrile and a,b-unsaturated cycloke-tones in DMF solution were studied. At room temperature, 2-cyano-3-aryl-3-(1,2,3,4-tetrahydronaphthalen- 1-on...A series of KF/Al2O3 catalyzed Michael-addition reactions between malononitrile and a,b-unsaturated cycloke-tones in DMF solution were studied. At room temperature, 2-cyano-3-aryl-3-(1,2,3,4-tetrahydronaphthalen- 1-one-2-yl) propionitrile derivatives were synthesized by the reaction between 2-arylmethylidene-1,2,3,4-tetra-hydronaphthalen-1-one and malononitrile. However, if the temperature was increased to 80 ℃, 2-amino-3-cyano-4- aryl-4H-benzo[h]chromene derivatives were obtained in high yields. When the a,b-unsaturated ketones were re-placed by 2,6-biarylmethylidenecyclohexanone or 2,5-biarylmethylidenecyclopentanone, another series of 2-amino- 3-cyano-4H-pyran derivatives was isolated successfully. The structures of the products were confirmed by X-ray diffraction analysis.展开更多
An environmentally benign un-catalyzed one-pot synthesis of 4,4＇-（arylmethylene）bis（1H-pyrazol-5-ols） has been reported via tandem Knoevenagel-Michael reaction of aldehydes with two equivalents of 3-methyl-1-phen...An environmentally benign un-catalyzed one-pot synthesis of 4,4＇-（arylmethylene）bis（1H-pyrazol-5-ols） has been reported via tandem Knoevenagel-Michael reaction of aldehydes with two equivalents of 3-methyl-1-phenyl-1H-pyrazol-5（4H）-one in aqueous medium.展开更多
基金support for this work provided by the NSF (CHE-0704015)
文摘A new organocatalytic enantioselective Michael addition of α-fluoromalonate to enals has been developed.The process is efficiently catalyzed by readily available chiral diphenylpyrolinol TES ether under mild reaction conditions to afford versatile highly enantioenriched fluorinated aldehydes.
文摘Phthalimide derivatives as nitrogen nucleophiles with α,β-unsaturated aldehydes for asymmetric aza-Michael additions have been reported. The reactions proceed smoothly to afford corresponding Michael adducts in good yields （up to 98%） and enantioselectivities （up to 95% ee）.
基金Project supported by the Foundation of the "urpassing Project"of Jiangsu Province.
文摘A series of KF/Al2O3 catalyzed Michael-addition reactions between malononitrile and a,b-unsaturated cycloke-tones in DMF solution were studied. At room temperature, 2-cyano-3-aryl-3-(1,2,3,4-tetrahydronaphthalen- 1-one-2-yl) propionitrile derivatives were synthesized by the reaction between 2-arylmethylidene-1,2,3,4-tetra-hydronaphthalen-1-one and malononitrile. However, if the temperature was increased to 80 ℃, 2-amino-3-cyano-4- aryl-4H-benzo[h]chromene derivatives were obtained in high yields. When the a,b-unsaturated ketones were re-placed by 2,6-biarylmethylidenecyclohexanone or 2,5-biarylmethylidenecyclopentanone, another series of 2-amino- 3-cyano-4H-pyran derivatives was isolated successfully. The structures of the products were confirmed by X-ray diffraction analysis.
基金the University Grants Commission,New Delhi,India(No.MRP 32-245/2006 SR) for the financial support
文摘An environmentally benign un-catalyzed one-pot synthesis of 4,4＇-（arylmethylene）bis（1H-pyrazol-5-ols） has been reported via tandem Knoevenagel-Michael reaction of aldehydes with two equivalents of 3-methyl-1-phenyl-1H-pyrazol-5（4H）-one in aqueous medium.
