pharmaceutical drug synthesis. We herein report a mild pathway for the efficient enantioselective synthesis of these compounds directly from aldehydes through synergistic cooperation between a neutral eosin Y hydrogen atom transfer photocatalyst and a chiral rhodium Lewisacid catalyst. This method is distinguished by its operational simplicity, abundant feedstocks, atom economy, and ability to generate products
Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Imines with Propioloylpyrazoles Induced by Chiral π–Cation Catalysts
作者:Masahiro Hori、Akira Sakakura、Kazuaki Ishihara
DOI:10.1021/ja508441t
日期:2014.9.24
We developed 1,3-dipolarcycloadditions of azomethine imines with propioloylpyrazoles catalyzed by a chiral copper(II) complex of 3-(2-naphthyl)-l-alanine amide. The asymmetric environment created by intramolecular π-cation interaction and the N-alkyl group of the chiral ligand gives the corresponding adducts in high yields with excellent enantioselectivity. This is the first successful method for
我们开发了由 3-(2-萘基)-l-丙氨酸酰胺的手性铜 (II) 配合物催化的偶氮甲碱亚胺与丙炔吡唑的 1,3-偶极环加成反应。由分子内 π-阳离子相互作用和手性配体的 N-烷基产生的不对称环境以高产率提供了相应的加合物,并具有出色的对映选择性。这是第一个成功的催化对映选择性 1,3-偶极环加成反应的偶氮甲亚胺与内部炔烃衍生物的方法,得到完全取代的吡唑啉。
Catalytic Enantioselective 1,3-Dipolar Cycloadditions of Nitrones with Propioloylpyrazoles and Acryloylpyrazoles Induced by Chiral π-Cation Catalysts
catalyzes the enantioselective1,3-dipolarcycloaddition reaction of nitrones with propioloylpyrazole and acryloylpyrazole derivatives. The asymmetric environment created by intramolecular π-cation interaction gives the corresponding adducts in high yields with excellent enantioselectivity. This is the first successful method for the catalytic enantioselective1,3-dipolarcycloaddition of nitrones with acetylene
3-(2-萘基)-l-丙氨酸酰胺的手性铜 (II) 配合物成功催化硝酮与丙炔基吡唑和丙烯酰吡唑衍生物的对映选择性 1,3-偶极环加成反应。由分子内 π-阳离子相互作用产生的不对称环境以高产率提供相应的加合物,并具有出色的对映选择性。这是硝酮与乙炔衍生物的催化对映选择性 1,3-偶极环加成反应的第一个成功方法。1,3-偶极环加合物可以通过使用 SmI(2) 还原裂解 NO 键而立体选择性地转化为 β-内酰胺。
Thorpe–Ingold Effect on High-Performance Chiral π–Copper(II) Catalyst
作者:Kazuaki Ishihara、Kazuki Nishimura
DOI:10.1055/a-1750-8481
日期:2022.4
The Thorpe–Ingold effect was applied to the design of a chiral ligand of π–copper(II) catalysts for the enantioselective α-fluorination of N-acyl-3,5-dimethylpyrazoles, and also for the enantioselective Mukaiyama–Michael, Diels–Alder, and 1,3-dipolar cycloaddition reactions of N-acryloyl-3,5-dimethylpyrazoles. The use of β,β-dimethyl-β-arylalanine-type ligand gave desired products with higher enantioselectivity
Catalytic Enantioselective [2 + 4] and [2 + 2] Cycloaddition Reactions with Propiolamides
作者:Kazuaki Ishihara、Makoto Fushimi
DOI:10.1021/ja8015318
日期:2008.6.18
We report here the catalytic and highly enantioselective [2 + 4] and [2 + 2] cycloaddition reactions of electron-rich dienes or silyl enol ethers with electron-deficient propiolamide derivatives induced by copper(II)center dot 3-(2-naphthyl)-L-alanine amide complex.