通过在温和的条件下通过铜催化的磷化磷与烯基硼酸的氧化偶联反应,开发了一种可调谐策略,以高至极好的收率制备α,β-不饱和酯和α,β-不饱和γ-酮酯。不加水的反应得到α,β-不饱和酯,酮和酰胺,而α,β-不饱和γ-酮酯,1,4-α,β-不饱和二酮和α,β-不饱和γ-酮酰胺是使用5.0当量时获得。水。高2 O 18标记实验表明,水在α,β-不饱和γ-酮酸酯的形成中起着重要作用。在机理研究的基础上,提出了α,β-不饱和酯和α,β-不饱和γ-酮酯的合理形成机理。salts盐也可以代替磷化磷化物直接用作偶联伴侣。该反应表现出广泛的底物范围,良好的官能团耐受性,良好的区域选择性和多种偶联产物。
report a visible-light-induced three-component reaction involving [1.1.1]propellane, diazoates, and various heterocycles for the synthesis of 3-heteroarylbicyclo[1.1.1]pentane-1-acetates. Throughout this reaction, the radicals generated from diazoate species react with [1.1.1]propellane in an addition reaction to form bicyclo[1.1.1]pentane (BCP) radicals that subsequently react with heterocycles, leading
Photodriven Radical-Polar Crossover Cyclization Strategy: Synthesis of Pyrazolo[1,5-<i>a</i>]pyridines from Diazo Compounds
作者:Peng Zhao、Yanbo Liu、Yuting Zhang、Lei Wang、Yongmin Ma
DOI:10.1021/acs.orglett.4c00812
日期:2024.3.29
This work demonstrates the synthesis of a variety of perfluoroalkyl heterocycles via a visible-light-driven radical-polar crossover cyclization strategy. In this process, single-electron reduction/SNV-type/cyclization sequences follow the radical addition reaction of a diazoester, which differs from the current role of diazoesters as radical precursors/acceptors. This transformation demonstrates excellent
这项工作展示了通过可见光驱动的自由基-极性交叉环化策略合成各种全氟烷基杂环。在此过程中,单电子还原/ SN V型/环化序列遵循重氮酯的自由基加成反应,这与目前重氮酯作为自由基前体/受体的作用不同。这种转化表现出优异的官能团相容性,并允许用重氮酯修饰许多生物活性分子。这种反应可能代表了重氮化合物光化学转化的一种新方法。
Pyrimidine-2-sulphides and their S-oxides for use in medicine, pharmaceutical compositions containing them, processes for their preparation and such compounds when novel per se
申请人:NYEGAARD & CO. A/S
公开号:EP0033195A1
公开(公告)日:1981-08-05
Compounds of the formula
(wherein X represents a halogen atom; nis 0,1 or 2; R1 and R2, which may be the same or different, each represents a hydrogen atom or a carboxyl, esterified carboxyl, amido or mono-or di-C1-4 alkylamido group or a C1-4 alkyl group which may if desired carry a carboxyl or esterified carboxyl group; and R3 represents a Ci-32 saturated or unsaturated, straight or branched, cyclic or acyclic aliphatic group or an araliphatic or heterocyclic substituted aliphatic group, a heterocyclic group or an aryl group which groups may if desired carry one or more substituents selected from halogen atoms and oxo, nitro, hydroxy, etherified hydroxy, esterified hydroxy, primary, secondary or tertiary amino, acylamino etherified mercapto or S = 0 or -SO2 derivatives thereof and esterified phosphoric acid groups) and, where an acidic or basic group is present, physiologically compatible salts thereof have been found to be of use in combating abnormal cell proliferation. The compounds are prepared inter alia by oxidation of the corresponding sulfide, displacement of a leaving atom or group from the 2-position of the pyrimidine by reaction with a sulfinic acid or by ring closure of the pyrimidine ring.