Stable azomethine imines having a 3,4-dihydroisoquinoline fragment and their cycloaddition to N-arylmaleimides
摘要:
Aroylation of 5,6,8,8a,13,14,16,16a-octahydro[1,2,4,5]tetrazino[6,1-a:3,4-a']diisoquinoline or 1,3,4,8b-tetrahydro[1,2]diazireno[3,1-a]isoquinoline, as well as reactions of 2-(2-bromoethyl)benzaldehyde with aroylhydrazines followed by treatment with triethylamine, led to the formation of stable azomethine imines, aroyl(3,4-dihydroisoquinolinium-2-yl)azanides. 1,3-Dipolar cycloaddition of the latter to N-mesitylmaleimide was stereoselective: the ratio of the trans- and cis-adducts was similar to(3-7): 1, the former prevailing. The reactions with N-arylmaleimides having no ortho-substituents in the aryl group gave the corresponding cis-adducts as the major products [trans/cis ratio similar to 1: (2.5-10)].
with azomethineimines has successfully been developed under mild reaction conditions, affording biologically interesting tetrahydropyrazoloisoquinoline derivatives in high to excellent yields and with excellent stereoselectivity. The reaction follows a tandem [3+2] cycloaddition/allylation/elimination of AcOH pathway. Allenyl carbinol acetates also reacted well with in situ generated azomethine imine
N-Heterocyclic carbene-catalyzed [2+3] cyclocondensation of α-chloroaldehydes with azomethine imines
作者:Zhong-Hua Gao、Xiang-Yu Chen、Jin-Tang Cheng、Wei-Lin Liao、Song Ye
DOI:10.1039/c5cc01238d
日期:——
The N-heterocyclic carbene-catalyzed enantioselective [2+3] cyclocondensation of α-chloroaldehydes with azomethine imines was developed to give the corresponding pyrazolidinones in good yields with excellent enantioselectivities.
The thermal1,3-dipolarcycloadditions of 4-acetoxyallenoates 1 with various dipoles have been reported. When azomethine imines and nitrones are used as the 1,3-dipole partner, the corresponding reactions afford 2,3-dihydropyrazole and 2,3-dihydroisoxazole derivatives, respectively. These reactions might proceed via a thermal1,3-dipolarcycloaddition and the subsequent elimination of HOAc. In addition
Asymmetric Synthesis of Tetrahydroisoquinoline Derivatives through 1,3-Dipolar Cycloaddition of C,N-Cyclic Azomethine Imines with Allyl Alkyl Ketones
作者:Guipeng Feng、Guoyang Ma、Wenyan Chen、Shaohong Xu、Kaikai Wang、Shaoyan Wang
DOI:10.3390/molecules26102969
日期:——
[3 + 2] A 1,3-Dipolarcycloaddition of C,N-cyclicazomethineimines with allyl alkyl ketones has been achieved. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. An array of tetrahydroisoquinoline derivatives is generally constructed with good diastereoselectivities and enantioselectivities (up to >25:1 dr, >95% ee). Moreover, the absolute configuration of
Palladium-Catalyzed Asymmetric Tandem [3+2] Cycloaddition/Allylation Reaction of Methylene-Trimethylenemethane: Access to Chiral Tricyclic Dinitrogen-Fused Heterocycles
A palladium-catalyzed asymmetric tandem [3+2] cycloaddition/allylation of methylene-trimethylenemethane is presented, providing the functionalized chiral hexahydropyrazolo[5,1-a]isoquinoline derivatives in high yields with good to excellent enantioselectivities and moderate to good E:Z ratios. In the one-pot sequential tandemreactions/hydroxylation, (E)-allylic alcohol products were obtained in good
提出了钯催化的亚甲基三亚甲基甲烷的不对称串联[3 + 2]环加成/烯丙基化反应,以高收率提供了功能化的手性六氢吡唑并[5,1- a ]异喹啉衍生物,具有良好的至优异的对映选择性和中等至良好的E:Z比率。在一锅顺序串联反应/羟基化中,以高收率获得具有优异对映选择性的(E)-烯丙醇产物。