abundant alkyl esters to afford amide bonds with exquisite selectivity by acyl C-O bond cleavage. The utility of this process is showcased by a broad scope of the method, including various sensitive functional groups, late-stage modification and the synthesis of drug molecules (>80 examples). Remarkable selectivity towards different functional groups and within different amide and ester electrophiles
酰胺键是化学和生物学中最基本的官能团之一,在许多简化关键药物和工业分子合成的过程中发挥着核心作用。尽管酰胺的合成是学术和工业科学家最常进行的反应之一,但由于该过程不利的动力学和热力学贡献,叔酰胺的直接转酰胺具有挑战性。在此,我们报告了第一种通用的、温和的和高度化学选择性的方法,用于通过非亲核胺的直接酰基 NC 键裂解对未活化的叔酰胺进行转酰胺。这种操作简单的方法是在没有过渡金属的情况下进行的,并且在异常温和的反应条件下进行。在这种情况下,我们进一步描述了大量烷基酯的直接酰胺化,以通过酰基 CO 键裂解提供具有极好的选择性的酰胺键。该方法的广泛应用展示了该过程的实用性,包括各种敏感的官能团、后期修饰和药物分子的合成(> 80 个例子)。观察到对不同官能团以及不同酰胺和酯亲电试剂的显着选择性,这是使用现有方法不可行的。进行了广泛的实验和计算研究,以深入了解高选择性的机制和起源。我们进一步提出了
The synthesis of bridged-ring carbo- and hetero-cycles via palladium catalysed regiospecific cyclisation reactions
A catalyst system comprising 10 mol % (Pd(OAc) and 20 mol % PPh3 effects the cyclisation of aryl halides onto proximate alkenes via 5-, 6-, and 7-exo-trig, and 7-endo-trig processes giving a variety of bridged-ring carbo- and hetero-cycles in excellent yield. Double bond isomerisation in the product is rarley encountered and may be suppressed by the addition of Tl(1) salts. One example of diastereospecific
Various N-vinyl- and N-allyl-amides of 2-iodobenzoic acid undergo catalytic cyclisation in the presence of tetraethylammonium chloride and a palladium acetate-based catalyst system to generate a range of synthetically useful structural features including tetrasubstitutedcarboncentres, and spiro- and bridged-ringcompounds, and in which 5-exo-trig cyclisations are kinetically favoured.
Intramolecular alkene arylations for rapid assembly of polycyclic systems containing quaternary centers. A new synthesis of spirooxindoles and other fused and bridged ring systems
作者:Matthew M. Abelman、Taeboem Oh、Larry E. Overman
DOI:10.1021/jo00227a038
日期:1987.9
GRIGG R.; SRIDHARAN V.; STEVENSON P.; WORAKUN T., J. CHEM. SOC. CHEM. COMMUN.,(1986) N 23, 1697-1699
作者:GRIGG R.、 SRIDHARAN V.、 STEVENSON P.、 WORAKUN T.