Iridium-catalyzed direct asymmetric vinylogous allylic alkylation
作者:Chang-Yun Shi、Jun-Zhao Xiao、Liang Yin
DOI:10.1039/c8cc07249c
日期:——
alkylation of α,β-unsaturated lactones (including coumarins) was achieved with excellent regio- and enantioselectivity. Transformations of the product were carried out by means of the versatile terminal olefin and lactonemoieties. The synthetic application of the present methodology was showcased by the asymmetric synthesis of an advanced synthetic Merck intermediate toward a new drug candidate.
Iridium‐Catalyzed Propenylation Reactions for the Synthesis of 4‐Pyridone Derivatives
作者:Xue‐dan Bai、Jie Wang、Ying He
DOI:10.1002/adsc.201801177
日期:2019.2
propenylation reaction of allylic carbonates with 4‐hydroxypyridine derivatives. The process efficiently provides 4‐pyridone derivatives with high stereoselectivities under mild conditions. The products could constitute valuable building blocks for the synthesis of natural products and other bioactive molecules. Preliminary mechanistic studies indicated that a tandemallylic substitution/isomerization
作者:Can-Can Bao、Dong-Song Zheng、Xiao Zhang、Shu-Li You
DOI:10.1021/acs.organomet.8b00762
日期:2018.12.24
N-Heterocyclic carbenes (NHCs) were found to be suitable ligands in Ir-catalyzed intermolecular allylic alkylation reaction. In the presence of a catalyst derived from [Ir(dncot)Cl]2 (dncot = dinaphthocyclooctatetraene) and triazolium salt L7, the alkylation products from the reaction of aryl allyl carbonates with sodium dialkyl malonates could be obtained in 85–99% yields favoring the formation of
发现N-杂环卡宾(NHC)是Ir催化的分子间烯丙基烷基化反应中的合适配体。在[Ir(dncot)Cl] 2(dncot =二萘环辛酸酯四烯)和三唑鎓盐L7衍生的催化剂存在下,芳基烯丙基碳酸酯与二烷基丙二酸钠的反应可得到烷基化产物,收率高达85-99%,形成支链产物(90/10→> 99/1 b / l)。此外,手性二氢异喹啉型NHC(DHIQ-NHC)(L8)已成功应用于Ir催化的不对称烯丙基烷基化反应中。对于广泛的底物,获得了优异的对映选择性和中等的区域选择性。
Asymmetric synthesis of quaternary α-trifluoromethyl α-amino acids by Ir-catalyzed allylation followed by kinetic resolution
作者:Xi-Shang Sun、Qiu Ou-Yang、Shi-Ming Xu、Xing-Heng Wang、Hai-Yan Tao、Lung Wa Chung、Chun-Jiang Wang
DOI:10.1039/d0cc00845a
日期:——
Facile access to quaternary α-trifluoromethyl α-amino acids has been developed. This sequential reaction involves an Ir-catalyzed asymmetric allylation of α-trifluoromethyl aldimine esters followed by an unprecedented kinetic resolution.
Palladium-Catalyzed Regio-, Diastereo-, and Enantioselective Allylation of Nitroalkanes with Monosubstituted Allylic Substrates
作者:Xiao-Fei Yang、Wei-Hua Yu、Chang-Hua Ding、Qiu-Ping Ding、Shi-Li Wan、Xue-Long Hou、Li-Xin Dai、Pin-Jie Wang
DOI:10.1021/jo400663d
日期:2013.7.5
Pd-catalyzed asymmetric allylic alkylation of nitroalkanes and monosubstituted allylic substrates was performed to afford products with two adjacent chiral centers and with excellent regio-, diastereo-, and enantioselectivities. The usefulness of the protocol in organic synthesis was demonstrated by transformation of the product to an opticallyactive homoallylamine, a 2,3-disubstituted tetrahydropyridine