苯并恶唑、苯并噻唑和苯并咪唑的高效合成因其优异的生物活性而备受关注。然而,在多相催化体系中开发环境友好且抗中毒的催化剂仍然是一个严峻的挑战。在此,通过沸石咪唑酯骨架(ZnCo-ZIF)的轻松热解制备了原子分散的Co 1 /NC催化剂。 Co 1 /NC催化剂表现出优异的氧化催化、抗硫和可重复使用性能。 Co 1 /NC的质量比活度(MSA)高达42.0 mol 2-PBO mol Co -1 h -1,远高于Co/NC纳米催化剂的质量比活度(15.6 mol 2-PBO mol Co -1 h -1 )。机理研究表明,O 2被原子分散的Co活性物质激活,形成1 O 2和˙O 2 -,它们负责关键亚胺中间体的脱氢,生成2-苯基苯并恶唑(2-PBO)。目前的工作代表了一种使用高效、稳定和绿色多相催化剂合成生物活性杂环化合物的新颖可行的策略。
Synthesis of 2-substituted pyrimidines and benzoxazoles via a visible-light-driven organocatalytic aerobic oxidation: enhancement of the reaction rate and selectivity by a base
作者:Lin Wang、Zhi-Gang Ma、Xiao-Jing Wei、Qing-Yuan Meng、Deng-Tao Yang、Shao-Fu Du、Zi-Fei Chen、Li-Zhu Wu、Qiang Liu
DOI:10.1039/c4gc00337c
日期:——
An efficient visible-light-driven photocatalytic oxidation of various 2-substituted dihydropyrimidines and phenolic imines has been achieved using an organic photocatalyst eosin Y bis(tetrabutyl ammonium salt) (TBA-eosin Y) and inexpensive oxidant molecular oxygen. With the aid of a base, significantly enhanced photoinduced electron transfer from substrates dihydropyrimidines or phenolic imines to the excited state of TBA-eosin Y has enabled the aerobic oxidation to yield 2-(methylthio)pyrimidines or 2-arylbenzoxazoles selectively.
In sharp contrast to hypervalent iodine(III) compounds, the isoelectronic bromine(III) counterparts have been little studied to date. This knowledge gap is mainly attributed to the difficult-to-control reactivity of λ3-bromanes as well as to their challenging preparation from the highly toxic and corrosive BrF3 precursor. In this context, we present a straightforward and scalable approach to chelation-stabilized
Intermolecular addition of alkyl radicals to imines in the absence and in the presence of a Lewis acid
作者:Nis Halland、Karl Anker Jørgensen
DOI:10.1039/b101762o
日期:——
benzaldehyde. The intermolecularradicaladdition can be carried out for different types of imines with alkyl and alkoxyalkyl radicals and it is demonstrated that it is possible to perform the radicaladdition in a catalytic enantioselective fashion with moderate yield and enantioselectivity. On the basis of the experimental results and theoretical calculations the mechanism for the radicaladdition to imines
[EN] BENZYLETHER AND BENZYLAMINO BETA-SECRETASE INHIBITORS FOR THE TREATMENT OF ALZHEIMER'S DISEASE<br/>[FR] INHIBITEURS DE BENZYLETHER ET BENZYLAMINO DE BETA-SECRETASE POUR TRAITER LA MALADIE D'ALZHEIMER
申请人:MERCK & CO INC
公开号:WO2005051914A1
公开(公告)日:2005-06-09
The present invention is directed to benzylether and benzylamino derivative compounds which are inhibitors of the beta-secretase enzyme and that are useful in the treatment of diseases in which the beta-secretase enzyme is involved, such as Alzheimer's disease. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the treatment of such diseases in which the beta-secretase enzyme is involved.
Chiral Zirconium Catalysts Using Multidentate BINOL Derivatives for Catalytic Enantioselective Mannich-Type Reactions; Ligand Optimization and Approaches to Elucidation of the Catalyst Structure
Catalytic enantioselective Mannich-type reactions of silicon enolates with aldimines were investigated using chiral zirconium catalysts prepared from Zr(O(t)Bu)(4), N-methylimidazole, and newly designed multidentate BINOL derivatives. These new multidentate BINOL ligands were designed on the basis of an assumed transition state structure of a chiral zirconium catalyst derived from two molecules of