Deacylative Allylation of Nitroalkanes: Unsymmetric Bisallylation by a Three-Component Coupling
作者:Alexander J. Grenning、Jon A. Tunge
DOI:10.1002/anie.201006273
日期:2011.2.11
Use it and lose it! Allylic alcohols were used directly for the synthesis of diallylated nitroalkanes in a three‐component coupling based on the strategy of deacylativeallylation for the in situ generation of a nucleophile and an allyl electrophile (see scheme).
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、
Nickel-Catalyzed Ring-Opening Allylation of Cyclopropanols via Homoenolate
We report herein a nickel-catalyzed ring-opening allylation of cyclopropanols with allylic carbonates that occurs under mild and neutral conditions. The reaction displays linear selectivity for both linear and branched acyclic allylic carbonates and is also applicable to cyclic allylic carbonates, affording a variety of δ,ε-unsaturated ketones in moderate to good yields. Mechanistic experiments are
Nucleophile Coordination Enabled Regioselectivity in Palladium‐Catalyzed Asymmetric Allylic C−H Alkylation
作者:Lian‐Feng Fan、Shi‐Wei Luo、Shu‐Sen Chen、Tian‐Ci Wang、Pu‐Sheng Wang、Liu‐Zhu Gong
DOI:10.1002/anie.201908960
日期:2019.11.18
Branched selectivity in asymmetric allylic C-H alkylation is enabled by using 2-acylimidazoles as nucleophiles in the presence of a chiral phosphoramidite-palladium catalyst. A wide range of terminal alkenes, including 1,4-dienes and allylarenes, are nicely tolerated and provide chiral 2-acylimidazoles in moderate to high yields and with high levels of regio-, and enantio-, and E/Z-selectivities. Mechanistic
Catalytic Asymmetric Synthesis of α-Tetrasubstituted α-Trifluoromethyl Homoallylic Amines by Ir-Catalyzed Umpolung Allylation of Imines
作者:Yingwei Wang、Li-Fan Deng、Xia Zhang、Dawen Niu
DOI:10.1021/acs.orglett.9b02550
日期:2019.9.6
homoallylic amines is established. This reaction, which involves an Ir-catalyzed umpolung allylation of imines and a 2-aza-Cope rearrangement cascade, could yield both tetrasubstituted and trisubstituted stereocenters. This transformation employs readily available starting materials and displays broad substrate scope. The isolation and structural determination of reaction intermediates revealed factors critical