本文描述了多种相对不稳定的碳亲核试剂的烯丙基烷基化的新方法。在这个“脱酰基烯丙基化”过程中,偶联伙伴,烯丙醇和酮亲核试剂,进行原位逆克莱森活化以生成烯丙乙酸和碳负离子。在钯的存在下,这些反应性中间体进行催化偶联形成新的 CC 键。与单分子脱羧烯丙基化(一种常用的碳阴离子烯丙基化方法)相比,脱酰基烯丙基化是一种分子间过程。此外,脱酰基烯丙基化允许容易获得的烯丙醇直接偶联。最后,通过快速构建多种 1、
Cu(II)-catalyzed highly enantioselective intramolecular cyclization of N-alkenylureas was developed for the concise assembly of chiral vicinal diamino bicyclic heterocycles. Facile removal of carbonyl group of the carbamido moiety allowed for ready access to enantioenriched cyclic vicinal diamines.
I<sub>2</sub>-Mediated oxidative bicyclization of 4-pentenamines to prolinol carbamates with CO<sub>2</sub> incorporating oxyamination of the CC bond
作者:Sheng Wang、Xiaowei Zhang、Chengyao Cao、Chao Chen、Chanjuan Xi
DOI:10.1039/c7gc01992k
日期:——
oxyamination reaction of alkenes with ambient CO2 is reported. In the presence of I2 and DBU, CO2 is applied in situ as a protectinggroup to regulate the nucleophilicity of the aminogroup and facilitate the bicyclization of 4-pentenamines with high chemoselectivity. Moreover, this reaction provided a feasible approach to prepare prolinol carbamates with good tolerance of functional groups and high efficiency
chemistry because of its wide occurrence in a variety of biological and pharmaceutical molecules. We report an efficient metal‐free, highly stereoselective intramolecular diamination using a novel chiral hypervalentiodine reagent together with its application as an efficient catalyst for the synthesis of diamines.
clean method has been developed for the α‐allylation of phenyl and alpha alkyl phenyl acetonitrile with allylic alcohols. The reaction is catalyzed by nickel complexes in situ generated from a combination of Ni(cod)2 and the dppf ligand and performed at 80 °C in methanol as reaction solvent. Accordingly to this simple and base‐free protocol that only yields water as a side‐product, many allylic nitriles
Pd-Catalyzed Intramolecular Aminoalkylation of Unactivated Alkenes: Access to Diverse <i>N</i>-Heterocycles
作者:Liu Ye、Kai-Yip Lo、Qiangshuai Gu、Dan Yang
DOI:10.1021/acs.orglett.6b03295
日期:2017.1.20
A highly efficient palladium-catalyzedintramolecular aminoalkylation of unactivatedalkenes in the absence of an external ligand and oxidant is described. New C–N and C(sp3)–C(sp3) bonds are formed simultaneously. This general transformation allows for construction of diverse N-heterocycles. Mechanistic studies show that the process may involve a four-membered Pd(alkyl)amido intermediate.