An efficient method for the construction of dibenzo[b,d]azepines containing two distinct stereogenic elements in a highly diastereoselective fashion is described. The key of the [5 + 2] reaction is to form a π-allylpalladium species through sequential C–H activation and regiospecific migratory insertion of the diene. This observation contrasts with the behavior of 1,2-alkenes that generally underwent
A novel Pd(0)-catalyzed intermolecular carbocyclization of phenol-derived biaryls with 1,3-dienes has been implemented through a sequence of oxidativeaddition to the C–I bond, regioselective olefin insertion, and allylative dearomatization. This method provides a broad range of attractive spirocyclic compounds bearing two contiguous tertiary/quaternary carbon centers in good yields with excellent
Palladium-Catalyzed Cascade sp<sup>2</sup>
C−H Functionalization/Intramolecular Asymmetric Allylation: From Aryl Ureas and 1,3-Dienes to Chiral Indolines
作者:Shu-Sen Chen、Min-Song Wu、Zhi-Yong Han
DOI:10.1002/anie.201702745
日期:2017.6.1
functionalization/intramolecular asymmetric allylation reaction is reported. A new chiral sulfoxide–oxazoline (SOX) ligand bearing single chiral center on the sulfur was identified as the optimal ligand for the reaction, being efficient both in the C−H cleavage step and the stereocontrol of the allylation step. The broad scope of this method with respect to aryl ureas and 1,3-dienes enables the rapid construction
报道了手性Pd II催化的级联sp 2 C H功能/分子内不对称烯丙基化反应。一种新的手性亚砜-恶唑啉(SOX)配体在硫上具有一个手性中心,被确定为该反应的最佳配体,在CH裂解步骤和烯丙基化步骤的立体控制方面均十分有效。关于芳基脲和1,3-二烯,该方法的广泛范围使得能够快速构建有价值的手性二氢吲哚衍生物,具有高收率和对映选择性(最高收率99%,最高收率95:5 er)。
Synthesis of Azepinoindoles via Rhodium-Catalyzed Formal Aza-[4 + 3] Cycloaddition Reaction of 3-Diazoindolin-2-imines with 1,3-Dienes in One-Pot
作者:Sanghyuck Kim、Hyunseok Kim、Kyusik Um、Phil Ho Lee
DOI:10.1021/acs.joc.7b01150
日期:2017.9.15
Rhodium-catalyzed formal aza-[4 + 3] cycloaddition reaction of 3-diazoindolin-2-imines with 1,3-dienes was demonstrated for the synthesis of azepinoindoles in good to excellent yields in one-pot. First, rhodium-catalyzed [2 + 1] cycloaddition reaction smoothly took place to produce iminyl vinyl cyclopropane intermediate at roomtemperature in chlorobenzene for 1 h, which was thermally converted to
One-Pot Synthesis of Indolizines via Sequential Rhodium-Catalyzed [2 + 1]-Cyclopropanation, Palladium-Catalyzed Ring Expansion, and Oxidation Reactions from Pyridotriazoles and 1,3-Dienes
作者:Hyunseok Kim、Sanghyuck Kim、Jiyeon Kim、Jeong-Yu Son、Yonghyeon Baek、Kyusik Um、Phil Ho Lee
DOI:10.1021/acs.orglett.7b02826
日期:2017.10.20
synthetic method for producing functionalized indolizine derivatives was developed via a Rh-catalyzed [2 + 1]-cyclopropanation, Pd-catalyzed ring expansion, and subsequent oxidation using manganese dioxide from pyridotriazoles and 1,3-dienes.