Enantioselective Diels−Alder Reaction of Simple α,β-Unsaturated Ketones with a Cinchona Alkaloid Catalyst
作者:Ravi P. Singh、Keith Bartelson、Yi Wang、Heng Su、Xiaojie Lu、Li Deng
DOI:10.1021/ja078251w
日期:2008.2.1
The simple α,β-unsaturated ketones and 2-pyrones are readily available and synthetically important dienophiles and dienes, respectively, for Diels−Alder reactions. However, both prove to be challenging substrates for catalytic asymmetric Diels−Alder reactions. By exploring a new catalysis strategy featuring cooperative catalysis with readily available cinchona catalysts, an unprecedented asymmetric
Organocatalytic Enantioselective Diels–Alder Reaction of 2‐Trifluoroacetamido‐1,3‐dienes with α,β‐Unsaturated Ketones
作者:Xin‐Qi Zhu、Qian Wang、Jieping Zhu
DOI:10.1002/anie.202214925
日期:2023.1.2
CPA-catalyzed annulation of 2-trifluoroacetamido-1,3-dienes with α,β-unsaturated carbonyl compounds affords highly functionalized 1-trifluoroacetamido cyclohex-1-ene derivatives 3 in high yields with excellent diastereo- and enantioselectivities. An asymmetric three-component reaction of 1, 2 and ortho-hydroxybenzhydryl alcohols 4 provides the densely functionalized hexahydroxanthenes with concurrent
Syntheses of α,β-Unsaturated Carbonyl Compounds from the Reactions of Monosubstituted Ozonides with Stable Phosphonium Ylides
作者:Yung-Son Hon、Ling Lu、Rong-Chi Chang、Sheng-Wun Lin、Pei-Pei Sun、Chia-Fu Lee
DOI:10.1016/s0040-4020(00)00903-0
日期:2000.11
Ozonides derived from terminal alkenes reacted with 1.3 mol equiv. of stable phosphonium ylides to give (E)-α,β-unsaturated carbonyl compounds in good to excellent yields. No reducing agent is needed in the reaction. However, alkoxyalkyl-substituted ozonides afforded a mixture of (Z)- and (E)-α,β-unsaturated carbonyl compounds under similar condition. The E/Z isomeric ratio is affected by the position
Utility of 2‐Diphenylphosphoryloxy‐1,3‐Dienes in Multicomponent Hetero‐Diels–Alder Reactions to Construct Functionalized Six‐Membered Nitrogen Heterocycles
作者:Qiuyu He、Lirong Cao、Yiran Wei、Gregory R. Dake
DOI:10.1002/chem.202201328
日期:2022.7.26
The utility of 2-diphenylphosphoryloxy-1,3-dienes for the construction of substituted six-membered nitrogen heterocycles is presented. These dienes undergo boron trifluoride-promoted aza-Diels-Alder reactions when reacted with imines or related species formed in situ using aldehydes and amine derivatives. The stability of the dienes allows this three-component reaction to be carried out with no special