Gold-Catalyzed Intermolecular [4+2] and [2+2+2] Cycloadditions of Ynamides with Alkenes
作者:Ramesh B. Dateer、Balagopal S. Shaibu、Rai-Shung Liu
DOI:10.1002/anie.201105921
日期:2012.1.2
As good as gold: Gold‐catalyzedintermolecular [4+2] cycloadditions of 2‐arylynamides with alkenes and gold‐catalyzed [2+2+2] cycloadditions of terminal ynamides with enol ethers have been developed (see scheme). The [4+2] cycloaddition is compatible with a range of alkenes and arylynamides and the [2+2+2] cycloaddition can also accommodate a variety of different arylynamide and enol ether substrates
Palladium-Catalyzed Cycloisomerization and Aerobic Oxidative Cycloisomerization of Homoallenyl Amides: A Facile and Divergent Approach to 2-Aminofurans
作者:Cungui Cheng、Shuiyou Liu、Gangguo Zhu
DOI:10.1021/acs.orglett.5b00464
日期:2015.3.20
including cycloisomerization and aerobic oxidative cycloisomerization of homoallenyl amides, is described. Varieties of functionalized 2-amino-5-alkylfurans and 2-amino-5-formylfurans can be selectively synthesized in good to excellent yields. Preliminary mechanistic studies show that peroxide may be a key intermediate for this Pd-catalyzed radical aerobic oxidative cycloisomerization of homoallenyl
Et2Zn-promoted β-trans-selective hydroboration of ynamide
作者:Kefeng Wang、Zixi Zhuang、Huihui Ti、Peishan Wu、Xin Zhao、Honggen Wang
DOI:10.1016/j.cclet.2019.11.008
日期:2020.6
Abstract The trans-hydroboration of alkyne represents a challenging task in organic synthesis. Reported herein is an Et2Zn promoted β-trans hydroboration of ynamides by using N-heterocyclic carbene (NHC)-ligated borane as boryl source. The reaction leads to a stereoselective construction of enamides bearing a valuable boryl substituent. Both aromatic and aliphatic ynamides were applicable to the reaction
Brønsted Acid Catalyzed Oxygenative Bimolecular Friedel–Crafts‐type Coupling of Ynamides
作者:Dilip V. Patil、Seung Woo Kim、Quynh H. Nguyen、Hanbyul Kim、Shan Wang、Tuan Hoang、Seunghoon Shin
DOI:10.1002/anie.201612471
日期:2017.3.20
A non‐metal approach for accessing α‐oxo carbene surrogates for a C−C bond‐forming bimolecularcoupling between ynamides and nucleophilic arenes was developed. This acid‐catalyzedcoupling features mild temperature, which is critical for the required temporal chemoselectivity among nucleophiles. The scope of nucleophiles includes indoles, pyrroles, anilines, phenols and silyl enolethers. Furthermore
开发了一种非金属的方法来获得α-氧代卡宾替代物,以实现酰胺和亲核芳烃之间形成C-C键的双分子偶联。这种酸催化的偶联具有适度的温度,这对于亲核试剂之间所需的时间化学选择性至关重要。亲核试剂的范围包括吲哚,吡咯,苯胺,苯酚和甲硅烷基烯醇醚。此外,通过使用手性N,N'-二氧化物提供了对S N 2'机理的直接测试,这也启发了相关金属催化过程中中间体的性质。
Gold-Catalyzed Formal [3 + 2] Cycloaddition of Ynamides with 4,5-Dihydro-1,2,4-oxadiazoles: Synthesis of Functionalized 4-Aminoimidazoles
作者:Wei Xu、Gaonan Wang、Ning Sun、Yuanhong Liu
DOI:10.1021/acs.orglett.7b01469
日期:2017.6.16
A gold-catalyzed formal [3 + 2] cycloaddition of ynamides with 4,5-dihydro-1,2,4-oxadiazoles has been developed. The reaction provides a concise and regioselective access to highly functionalized 4-aminoimidazoles likely via the formation of an α-imino gold carbene intermediate followed by cyclization. 4,5-Dihydro-1,2,4-oxadiazole was found to act as an efficient N-iminonitrene equivalent in these