Deacylative Allylation: Allylic Alkylation via Retro-Claisen Activation
作者:Alexander J. Grenning、Jon A. Tunge
DOI:10.1021/ja205717f
日期:2011.9.21
"deacylative allylation", the coupling partners, an allylic alcohol and a ketone pronucleophile, undergo in situ retro-Claisen activation to generate an allylic acetate and a carbanion. In the presence of palladium, these reactive intermediates undergo catalytic coupling to form a new C-C bond. In comparison to unimolecular decarboxylative allylation, a commonly utilized method for allylation of carbon
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、
Enantioselective Construction of Aryl-Substituted All-Carbon Quaternary Stereocenters by Using Tertiary Amine-Thiourea-Catalyzed Michael Additions
A catalytic enantioselective synthetic strategy for the aryl-substituted all-carbon quaternary stereocenters of bioactive hydrodibenzofuran alkaloids was achieved by the Michael addition reaction of α-cyano ketones and acrylates using a chiral tertiary amine–thiourea catalyst. This method can tolerate steric bulkiness and multiple functional groups, and 32 Michael adducts were prepared in good to excellent
An expeditious method to synthesize difluoroboron complexes of β-keto amides from β-keto nitriles and BF<sub>3</sub>·OEt<sub>2</sub>
作者:Chuangchuang Xu、Jiaxi Xu
DOI:10.1039/c7ob01356f
日期:——
synthesize difluoroboron complexes of β-keto amides has been developed fromβ-ketonitriles and BF3·OEt2. BF3·OEt2 serves as both a BF2 source and a Lewis acid catalyst in the synthetic strategy. The formation mechanism of the difluoroboron complexes fromβ-ketonitriles and BF3·OEt2 was proposed. The difluoroboron complexes can be further converted into β-keto amides by treatment with sodium acetate
Iodobenzene Dichloride/Zinc Chloride-Mediated Synthesis of <i>N</i>
-Alkoxyindole-3-carbonitriles from 3-Alkoxyimino-2-arylalkylnitriles via Intramolecular Heterocyclization
作者:Zhongxiang Yun、Ran Cheng、Jiyun Sun、Daisy Zhang-Negrerie、Yunfei Du
DOI:10.1002/adsc.201701111
日期:2018.1.17
heterocyclization of the readily available 3‐alkoxyimino‐2‐arylalkylnitriles mediated by iodobenzene dichloride/zinc chloride. The mechanism of the reaction proposes the formation of a key intermediate of nitrenium cation from a chlorination and dechlorination process facilitated by the hypervalent iodine reagent and Lewis acid respectively.