[3 + 2] Cycloaddition of Nitrile Imines with Enamides: An Approach to Functionalized Pyrazolines and Pyrazoles
作者:Liang Tu、Limei Gao、Xiaomeng Wang、Ruijie Shi、Rupei Ma、Junfei Li、Xiaoshuang Lan、Yongsheng Zheng、Jikai Liu
DOI:10.1021/acs.joc.0c02244
日期:2021.1.1
with enamides has been established. A wide range of functionalized pyrazoline derivatives (53 examples) were obtained in moderate to good yields (up to 96%) under very mild conditions. This protocol features broad substrate scope, good functional group tolerance, and operational simplicity. Practical transformation of the products into useful pyrazoles via a one-pot process and the scalability of this
Palladium-Catalyzed Direct Arylation of Cyclic Enamides with Aryl Silanes by sp2 CH Activation
作者:Hai Zhou、Yun-He Xu、Wan-Jun Chung、Teck-Peng Loh
DOI:10.1002/anie.200901884
日期:——
It does get in! A fluoride‐assisted direct cross‐coupling of cyclic enamides with trialkoxy aryl silanes by a palladium‐catalyzed CH activation leads to a wide range of enamides in yields of up to 95 %.
Direct arylation of cyclic enamides via Pd(ii)-catalyzed C–H activation
作者:Hai Zhou、Wan-Jun Chung、Yun-He Xu、Teck-Peng Loh
DOI:10.1039/b903151k
日期:——
A new direct coupling of cyclic enamides with aryl boronic acids viaPd(II)-catalyzed CâH functionalization has been achieved with good yields (up to 90%).
Enamides were efficiently prepared via a novel Rh/C-catalyzed direct hydroacylation of ketoximes. Up to 88% isolated yield of enamides were obtained with this method. Subsequent asymmetric hydrogenation of the enamides with Rh/DuanPhos complex gave the corresponding chiral amine in excellent enantioselectivities (up to 99.7% ee).
Brønsted Acid Catalyzed [3 + 2]-Cycloaddition of Cyclic Enamides with <i>in Situ</i> Generated 2-Methide-2<i>H</i>-indoles: Enantioselective Synthesis of Indolo[1,2-<i>a</i>]indoles
作者:Kalisankar Bera、Christoph Schneider
DOI:10.1021/acs.orglett.6b02898
日期:2016.11.4
An efficient formal [3 + 2]-cycloaddition toward the highly diastereo- and enantioselectivesynthesis of indolo[1,2-a]indoles is disclosed. A chiral BINOL-derived phosphoric acid catalyzed the highly enantioselective conjugate addition of cyclic enamides to in situ generated 2-methide-2H-indoles and subsequent aminalization to give rise to acetamide-substituted indolo[1,2-a]indoles carrying three contiguous
公开了向吲哚[1,2- a ]吲哚的高度非对映和对映选择性合成的有效形式[3 + 2]-环加成反应。手性BINOL衍生的磷酸催化环烯酰胺的高对映选择性共轭加成反应,使其原位生成2-甲基2 H-吲哚并随后进行醛化,生成带有3个连续氨基酸的乙酰胺取代的吲哚[1,2- a ]吲哚立体定向中心。重要的是,这些产物形成为单一非对映异构体,并具有优异的产率和对映选择性。在环境温度下温和的反应条件,对乙酰氨基基团的轻松除去以及放大的可能性凸显了该方法的实用性。