Silver-Catalyzed 1,3-Dipolar Cycloaddition of Azomethine Ylides with β-Boryl Acrylates
摘要:
The Ag-catalyzed 1,3-dipolar cycloaddition of (E)-beta-borylacrylates with azomethine ylides is described. The resulting 3-borylpyrrolidine derivatives were obtained in high yields and complete endo selectivities using AgOAc/dppe as catalyst system and B(dam) as boryl group. Transformation of the B(dam) group into pinacol borane and oxidation afforded 3-hydroxyproline derivatives in high yields.
Stereodivergent Synthesis of Chiral Fullerenes by [3 + 2] Cycloadditions to C<sub>60</sub>
作者:Enrique E. Maroto、Salvatore Filippone、Margarita Suárez、Roberto Martínez-Álvarez、Abel de Cózar、Fernando P. Cossío、Nazario Martín
DOI:10.1021/ja410408c
日期:2014.1.15
A wide range of new dipoles and catalysts have been used in 1,3-dipolar cycloadditions of N-metalated azomethine ylides onto C60 yielding a full stereodivergent synthesis of pyrrolidino[60]fullerenes with complete diastereoselectivities and very high enantioselectivities. The use of less-explored chiral α-iminoamides as starting 1,3-dipoles leads to an interesting double asymmetric induction resulting
Stereodivergency in Catalytic Asymmetric Conjugate Addition Reactions of Glycine (Ket)imines
作者:Hun Young Kim、Jian-Yuan Li、Sungkyung Kim、Kyungsoo Oh
DOI:10.1021/ja2100356
日期:2011.12.28
catalytic asymmetric conjugatereactions of glycine (ket)imines with nitroalkenes have been achieved using various chiral catalyst systems derivedfrom a multidentate amino alcohol (1). The stepwise nature of the [3 + 2] cycloaddition reactions of N-metalated azomethine ylides has also been demonstrated by highly enantio- and diastereoselective syntheses of exo-5 and endo-8 from the respective syn-4
Azomethine-isocyanide [3+2] cycloaddition to imidazoles promoted by silver and DBU
作者:Xiaoshan Huang、Xuefeng Cong、Pengbing Mi、Xihe Bi
DOI:10.1039/c7cc00772h
日期:——
A new silver-promoted [3+2] cycloaddition of azomethine ylides with isocyanides has been described to construct a variety of 1,2,4-trisubstituted imidazoles of vital bioactive molecules.
Enantioselective synthesis of 4-aminopyrrolidine-2,4-dicarboxylate derivatives via Ag-catalyzed cycloaddition of azomethine ylides with alkylidene azlactones
作者:María González-Esguevillas、Javier Adrio、Juan C. Carretero
DOI:10.1039/c3cc41663a
日期:——
A catalytic highly enantioselective silver–DTBM-segphos catalyzed cycloaddition of α-iminoesters with alkylidene azlactones is reported. This procedure provides an effective access to 4-aminopyrrolidine-2,4-dicarboxylate derivatives with high diastereo- and enantioselectivity.
Cu-Catalyzed Asymmetric 1,3-Dipolar Cycloaddition of Azomethine Ylides with β-Phenylsulfonyl Enones. Ligand Controlled Diastereoselectivity Reversal
作者:Rocío Robles-Machín、María González-Esguevillas、Javier Adrio、Juan C. Carretero
DOI:10.1021/jo902103z
日期:2010.1.1
A catalytic asymmetric procedure for the 1,3-dipolarcycloaddition of (Ε)-β-phenylsulfonyl enones with azomethineylides to provide highly functionalized pyrrolidine derivatives is described. In the presence of chiral CuI-Segphos catalysts the aducts were obtained with high regio-, diastereo-, and enantioselectivity. Interestingly, a switch from endo to exo selectivity was observed when Segphos or
描述了用于(E)-β-苯基磺酰基烯酮的1,3-偶极环加成与偶氮甲亚胺基化物以提供高度官能化的吡咯烷衍生物的催化不对称方法。在手性Cu I -SEgphOS催化剂的存在下,以高区域选择性,非对映异构体和对映体选择性获得了加合物。有趣的是,从一个交换机内到外使用SEGPHOS或DTBM-SEGPHOS配体时,观察选择性。