Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structura...Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.展开更多
(E)-α,β-Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)-(1Z,3Z)-dienolates as the major in the presence of a copper(I)-(R)-DTBM-SEGPHOS catalyst and EtgN,which react with aldimines to af...(E)-α,β-Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)-(1Z,3Z)-dienolates as the major in the presence of a copper(I)-(R)-DTBM-SEGPHOS catalyst and EtgN,which react with aldimines to afford syn-vinylogous products as the major dia-stereoisomers in high regio-and enantioselectivities.In some cases,the diastereoselectivity is low,possibly due to the low ratio of copper(I)-(1Z,3Z)-dienolates to copper(I)-(1Z,3E)-dienolates.展开更多
Dienols are important structural motifs in organic molecules,but most of the traditional synthetic methods required multistep prefunctionalization of substrates,leading to stoichiometric waste and low atom economy.Her...Dienols are important structural motifs in organic molecules,but most of the traditional synthetic methods required multistep prefunctionalization of substrates,leading to stoichiometric waste and low atom economy.Herein,we report a redox-neutral coupling of simple 1,3-dienes and aldehydes via nickel and Brønsted acid dual catalysis,providing a highly atom-economical and by-product-free route to various dienols with up to 94%yield and up to 50∶1 EE/EZ ratio.The use of 2-isopropoxyphenol as a Brønsted acid co-catalyst was critical to the reactivity and selectivity.展开更多
基金supported by the National Natural Science Foundation of China (21871116, U22A20390)the Fundamental Research Funds for the Central Universities (lzujbky-2023-stlt01)the“111” program from the MOE of China。
文摘Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.
基金We gratefully acknowledge the financial support from the"Thousand Youth Talents Plan",the National Natural Science Foundation of China(Nos.21672235,21871287,21922114)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XD20000000)+1 种基金CAS Key Laboratory of Synthetic Chemistry of Natural SubstancesShanghai Institute of Organic Chemistry.
文摘(E)-α,β-Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)-(1Z,3Z)-dienolates as the major in the presence of a copper(I)-(R)-DTBM-SEGPHOS catalyst and EtgN,which react with aldimines to afford syn-vinylogous products as the major dia-stereoisomers in high regio-and enantioselectivities.In some cases,the diastereoselectivity is low,possibly due to the low ratio of copper(I)-(1Z,3Z)-dienolates to copper(I)-(1Z,3E)-dienolates.
基金the National Natural Science Foundation of China(21672107 and 21871145)the Fundamental Research Funds for the Central Universities(Nankai University,63191601)the Tianjin Applied Basic Research Project and Cutting-Edge Technology Research Plan(19JCZDJC37900)for financial support.
文摘Dienols are important structural motifs in organic molecules,but most of the traditional synthetic methods required multistep prefunctionalization of substrates,leading to stoichiometric waste and low atom economy.Herein,we report a redox-neutral coupling of simple 1,3-dienes and aldehydes via nickel and Brønsted acid dual catalysis,providing a highly atom-economical and by-product-free route to various dienols with up to 94%yield and up to 50∶1 EE/EZ ratio.The use of 2-isopropoxyphenol as a Brønsted acid co-catalyst was critical to the reactivity and selectivity.
