Electrophilic Interaction of 2,3-Allenoates with PhSeCl. An Unexpected Highly Stereoselective Synthesis of 3-Phenylseleno-4-oxo-2(<i>E</i>)-alkenoates

We have previously reported an efficient synthesis of β-phenylselenium-substituted butenolides via electrophilic cyclization of 2,3-allenoates with PhSeCl in aqueous MeCN. However, when 2,3-allenoates were treated with PhSeCl in MeCN, 3-phenylseleno-4-oxo-2(E)-alkenoates were formed unexpectedly. The addition of Li2CO3 improved the yield and the selectivity of the reaction. A possible mechanism involving a decomposition of selenate esters was proposed

A Novel Synthesis of 1,3-Oxazine-2,4-diones via a Simple and Efficient Reaction of CO₂ with 2,3-Allenamides

A simple and efficient reaction of CO2 with 2,3-allenamides under mild conditions (CO2 balloon without any metal catalyst in the presence of K2CO3 or Cs2CO3) leads to an efficient synthesis of 1,3-oxazine-2,4-diones. The high reactivity of the allene moiety is crucial for the success of this transformation since the corresponding reaction of α,β-unsaturated alkenamides or alkynamides does not occur

A Novel Synthesis of 1,3-Oxazine-2,4-diones via a Simple and Efficient Reaction of CO₂ with 2,3-Allenamides

A simple and efficient reaction of CO2 with 2,3-allenamides under mild conditions (CO2 balloon without any metal catalyst in the presence of K2CO3 or Cs2CO3) leads to an efficient synthesis of 1,3-oxazine-2,4-diones. The high reactivity of the allene moiety is crucial for the success of this transformation since the corresponding reaction of α,β-unsaturated alkenamides or alkynamides does not occur

supplementary_material - Phenylethynyl-terminated oligoimides with ultra-low melt viscosity derived from 1,4-bis(3,4-dicarboxy phenoxy)benzene dianhydride

supplementary_material for Phenylethynyl-terminated oligoimides with ultra-low melt viscosity derived from 1,4-bis(3,4-dicarboxy phenoxy)benzene dianhydride by Wei Wang, Guofei Chen, and Xingzhong Fang in High Performance Polymers</p

Ring-Opening Cyclization of Alkylidenecyclopropyl Ketones with Amines. An Efficient Synthesis of 2,3,4-Trisubstituted Pyrroles

An efficient synthesis of 2,3,4-trisubstituted pyrroles via intermolecular cyclization of alkylidenecyclopropyl ketones with amines was observed. The addition of anhydrous MgSO4 improved the yields of the products 3. A possible mechanism involving the distal cleavage of the C−C bond of cyclopropane ring was proposed

Electrophilic Interaction of 2,3-Allenoates with PhSeCl. An Unexpected Highly Stereoselective Synthesis of 3-Phenylseleno-4-oxo-2(<i>E</i>)-alkenoates

We have previously reported an efficient synthesis of β-phenylselenium-substituted butenolides via electrophilic cyclization of 2,3-allenoates with PhSeCl in aqueous MeCN. However, when 2,3-allenoates were treated with PhSeCl in MeCN, 3-phenylseleno-4-oxo-2(E)-alkenoates were formed unexpectedly. The addition of Li2CO3 improved the yield and the selectivity of the reaction. A possible mechanism involving a decomposition of selenate esters was proposed

Ring-Opening Cyclization of Alkylidenecyclopropyl Ketones with Amines. An Efficient Synthesis of 2,3,4-Trisubstituted Pyrroles

An efficient synthesis of 2,3,4-trisubstituted pyrroles via intermolecular cyclization of alkylidenecyclopropyl ketones with amines was observed. The addition of anhydrous MgSO4 improved the yields of the products 3. A possible mechanism involving the distal cleavage of the C−C bond of cyclopropane ring was proposed

Supplemental Material Synthesis and characterization of epoxy resin composites modified by reactive polyimide containing hydroxyl groups

Supplemental Material for Synthesis and characterization of epoxy resin composites modified by reactive polyimide containing hydroxyl groups by Gang Xu, Liyun Tan, Yong Nie, Xingzhong Fang and Guofei Chen in High Performance Polymers</p

sj-pdf-1-hip-10.1177_09540083211052270 – Supplemental Material for Polyimides from 2,5-bis[4-(4-aminophenoxy)benzoyl]furan and their thermal crosslinking reaction

Supplemental Material, sj-pdf-1-hip-10.1177_09540083211052270 for Polyimides from 2,5-bis[4-(4-aminophenoxy)benzoyl]furan and their thermal crosslinking reaction by Kai Ma, Hanzhou Jiang, Guofei Chen, Wei Wang and Yonggang Zhang in High Performance Polymers</p

Pd(OAc)₂-Catalyzed Cyclization of 2,3-Allenoic Acids in the Presence of Terminal α,β-Unsaturated Alkynones: A One-Pot Highly Stereoselective Synthesis of 4-(3′-Oxo-1′(<i>E</i>)-alkenyl)-2(5<i>H</i>)-furanones

The Pd(OAc)2-catalyzed cyclization reaction of 2,3-allenoic acids in the presence of terminal α,β-unsaturated alkynones afforded an E/Z mixture of 4-(3′-oxo-1′-alkenyl)-2(5H)-furanones. A subsequent complete isomerization of the Z-isomer to E-isomer was observed in DMSO at 90 °C, which led to a highly stereoselective synthesis of 4-(3′-oxo-1′(E)-alkenyl)-2(5H)-furanones. A possible mechanism is proposed