Facile construction of novel imidazolidine-spirooxindoles via diastereoselective cycloaddition of N-acylhydrazine-derived imines with 3-isothiocyanato oxindoles
presence of 10 mol% of Na2CO3, the desired imidazolidine-spirooxindoles were obtained in 81–99% yield with up to 99 : 1 dr by means of the diastereoselective [3 + 2] cycloaddition of N-acylhydrazine-derived imines with 3-isothiocyanatooxindoles. Single-crystal X-ray structure analysis was conducted to determine the relative stereochemistry of the imidazolidine-spirooxindoles. Diastereoselective access
在存在10 mol%的Na 2 CO 3时,通过衍生自N-酰基肼的非对映选择性[3 + 2]环加成反应,可以81-99%的收率获得所需的咪唑烷-螺氧并吲哚,最高可达99:1 dr。亚胺与3-异硫氰酸根合吲哚。进行了单晶X射线结构分析,以确定咪唑烷-螺氧还吲哚的相对立体化学。拟议的机制假设非对映选择性进入咪唑烷-spirooxindoles。
Synthesis of amino-diamondoid pharmacophores <i>via</i> photocatalytic C–H aminoalkylation
作者:William K. Weigel、Hoang T. Dang、Hai-Bin Yang、David B. C. Martin
DOI:10.1039/d0cc02804e
日期:——
direct C–H aminoalkylation reaction using two light-activated H-atom transfer catalyst systems that enable the introduction of protected amines to native adamantane scaffolds with C–C bond formation. The scope of adamantane and imine reaction partners is broad and deprotection provides versatile amine and amino acid building blocks. Using readily available chiral imines, the enantioselective synthesis
我们报告了使用两种光活化 H 原子转移催化剂系统的直接 C-H 氨基烷基化反应,该反应能够将受保护的胺引入具有 C-C 键形成的天然金刚烷支架。金刚烷和亚胺反应伙伴的范围很广,去保护提供了通用的胺和氨基酸构建块。使用容易获得的手性亚胺,还描述了沙格列汀核心和金刚乙胺衍生物的对映选择性合成。
Asymmetric catalytic Mannich-type reaction of hydrazones with difluoroenoxysilanes using imidazoline-anchored phosphine ligand–zinc(ii) complexes
作者:Zhiliang Yuan、Liangyong Mei、Yin Wei、Min Shi、Padmanabha V. Kattamuri、Patrick McDowell、Guigen Li
DOI:10.1039/c2ob07022g
日期:——
Asymmetric Mannich-type reaction of hydrazones with difluoroenoxysilanes using chiral zinc(II)âimidazolineâphosphine complexes as catalysts have been established, giving the corresponding adducts in good to excellent enantioselectivity and chemical yields under mild conditions.
Allylation of N-Benzoylhydrazones (=N′-Alkylidene-Substituted Benzohydrazides) by Treatment with Allyl Bromide in the Presence of Zinc in Aqueous Ammonium Chloride Solution
N‐Benzoylhydrazones (=N′‐alkylidene‐substituted benzohydrazides) 1 are allylated efficiently by reaction with allyl bromide (2) in the presence of Zn in aqueous NH4Cl solution. The products 3 are formed in excellent yields (85–94%) within 35–50 min (Scheme, Table).
Ñ -Benzoylhydrazones(= N' -亚烷基-取代的benzohydrazides)1是由用烯丙基溴(反应有效地烯丙基化2中的Zn的在含水NH存在下)4 Cl溶液。产品3在35-50分钟内以优异的产率(85-94%)形成(方案,表)。
Tin Powder-Promoted One-Pot Construction of α-Methylene-γ-lactams and Spirolactams from Aldehydes or Ketones, Acylhydrazines, and 2-(Bromomethyl)acrylate
作者:Yanli Xu、Danfeng Huang、Ke-Hu Wang、Junyan Ma、Yingpeng Su、Ying Fu、Yulai Hu
DOI:10.1021/acs.joc.5b02154
日期:2015.12.18
A concise and efficient method for the synthesis of alpha-methylene-gamma-lactams is developed from multicomponent one-pot reactions of aldehydes or ketones, hydrazides, and ethyl 2-(bromomethyl)acrylate promoted by tin powder. The reaction proceeds smoothly under mild reaction conditions without using any catalyst to give the corresponding products in high yields. alpha-Methylene-gamma-spirolactams can also be prepared from cyclic ketones.