A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7：1-20：1 dr under the catalysis of L-diarylprolinol...A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7：1-20：1 dr under the catalysis of L-diarylprolinol silyl ether. This reaction provides a facile access to highly enantioenriched 4- diphenylphosphinyl chroman-2-ols. It also represents a novel organocatalytic asymmetric phospha- Michael addition of α,β-unsaturated aldehydes with pentavalent P-nucleophiles.展开更多
A phosphine-catalyzed [4＋2] annulation of a-substituted allenoate with exocyclic alkene moiety of oxindoles or indan-1,3-diones has been developed. Thus, under the catalysis of PPh3 （20 mol%）, a series of spirooxin...A phosphine-catalyzed [4＋2] annulation of a-substituted allenoate with exocyclic alkene moiety of oxindoles or indan-1,3-diones has been developed. Thus, under the catalysis of PPh3 （20 mol%）, a series of spirooxindole- or spiroindan-1,3-dione-cyclohexenes have been obtained in moderate to excellent yields and regioselectivity from the annulations of a-methyl allenoates with 3-methyleneoxindoles or 2-methyleneindan-1,3-diones. This method offers an easy access to structurally novel spirocyclohexenes.展开更多
in this work, the phosphine-catalyzed annulation reactions between modified allylic derivatives and polar 1,1-dicyano-1,3-dienes have been studied. In the catalysis of PPh3 （20 mol%）, a [4 ＋ 1 ] annulation reaction...in this work, the phosphine-catalyzed annulation reactions between modified allylic derivatives and polar 1,1-dicyano-1,3-dienes have been studied. In the catalysis of PPh3 （20 mol%）, a [4 ＋ 1 ] annulation reaction is realized between a series of l,l-dicyano-2,4-diaryl-1,3-dienes and ethoxycarbonyl-activated allylic acetate, producing polysubstituted cyclopentenes in modest to excellent yields. It is also observed that the substituents of both 1,3-dienes and allylic derivatives have a significant influence on the annulation mode： under the catalysis of PPh3 or PBu3 （20 mol%）, regioselective [3 ＋ 2] annulation products are formed from differently substituted substratcs.展开更多
Chiral 3-hydroxyoxindoles are biologically important molecular motifs which are frequently present in natural products and artificial compounds.Herein,we report an ultraviolet light-driven asymmetric vinylogous aldol ...Chiral 3-hydroxyoxindoles are biologically important molecular motifs which are frequently present in natural products and artificial compounds.Herein,we report an ultraviolet light-driven asymmetric vinylogous aldol reaction between versatile isatins and 2-alkylbenzophenones.Under mild conditions.展开更多
基金Financial support from the National Natural Science Foundation of China(Nos. 21472096, J1103306)
文摘A highly stereoselective asymmetric cascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%-99% ee and 7：1-20：1 dr under the catalysis of L-diarylprolinol silyl ether. This reaction provides a facile access to highly enantioenriched 4- diphenylphosphinyl chroman-2-ols. It also represents a novel organocatalytic asymmetric phospha- Michael addition of α,β-unsaturated aldehydes with pentavalent P-nucleophiles.
基金Financial support from the Fundamental Research Funds for the Central Universities （No. KYZ201749） and the National Natural Science Foundation of China （Nos. 21272119, J1103306） are gratefully acknowledged.
文摘A phosphine-catalyzed [4＋2] annulation of a-substituted allenoate with exocyclic alkene moiety of oxindoles or indan-1,3-diones has been developed. Thus, under the catalysis of PPh3 （20 mol%）, a series of spirooxindole- or spiroindan-1,3-dione-cyclohexenes have been obtained in moderate to excellent yields and regioselectivity from the annulations of a-methyl allenoates with 3-methyleneoxindoles or 2-methyleneindan-1,3-diones. This method offers an easy access to structurally novel spirocyclohexenes.
基金Acknowledgement Financial support from National Natural Science Foundation of China （Nos. 21072100 21121002 21272119） is gratefully acknowledged.
文摘in this work, the phosphine-catalyzed annulation reactions between modified allylic derivatives and polar 1,1-dicyano-1,3-dienes have been studied. In the catalysis of PPh3 （20 mol%）, a [4 ＋ 1 ] annulation reaction is realized between a series of l,l-dicyano-2,4-diaryl-1,3-dienes and ethoxycarbonyl-activated allylic acetate, producing polysubstituted cyclopentenes in modest to excellent yields. It is also observed that the substituents of both 1,3-dienes and allylic derivatives have a significant influence on the annulation mode： under the catalysis of PPh3 or PBu3 （20 mol%）, regioselective [3 ＋ 2] annulation products are formed from differently substituted substratcs.
基金Financial support from the National Natural Science Foundation of China(Grant No.22171143,21472096 and J1103306)is gratefully acknowledged.
文摘Chiral 3-hydroxyoxindoles are biologically important molecular motifs which are frequently present in natural products and artificial compounds.Herein,we report an ultraviolet light-driven asymmetric vinylogous aldol reaction between versatile isatins and 2-alkylbenzophenones.Under mild conditions.
