Catalytic Anti-Markovnikov Hydrobromination of Alkynes
作者:Mycah R. Uehling、Richard P. Rucker、Gojko Lalic
DOI:10.1021/ja503944n
日期:2014.6.18
We have developed the first catalytic method for anti-Markovnikovhydrobromination of alkynes. The reaction affords terminal E-alkenyl bromides in high yield and with excellent regio- and diastereoselectivity. Both aryl- and alkyl-substituted terminal alkynes can be used as substrates. Furthermore, the reaction conditions are compatible with a wide range of functional groups, including esters, nitriles
Solventless and metal-free regioselective hydrofluorination of functionalized alkynes and allenes: an efficient protocol for the synthesis of <i>gem</i>-difluorides
作者:Zhichao Lu、Bhvandip S. Bajwa、Shiwen Liu、Sheye Lee、Gerald B. Hammond、Bo Xu
DOI:10.1039/c8gc03876g
日期:——
The combination of two easily handled, highly acidic liquid HF complex reagents, DMPU-12HF and KHSO4-13HF, generated a highly acidic fluorination system that facilitated exclusive Markovnikov addition of HF to widely functionalized alkynes, including alkyne tethered drugs, or allenes to produce gem-difluorides with high atom economy, and with an easy workup.
Synthesis of Enantioenriched Allylic Silanes via Nickel-Catalyzed Reductive Cross-Coupling
作者:Julie L. Hofstra、Alan H. Cherney、Ciara M. Ordner、Sarah E. Reisman
DOI:10.1021/jacs.7b11707
日期:2018.1.10
asymmetric Ni-catalyzed reductive cross-coupling has been developed to prepare enantioenriched allylic silanes. This enantioselective reductive alkenylation proceeds under mild conditions and exhibits good functional group tolerance. The chiral allylic silanes prepared here undergo a variety of stereospecific transformations, including intramolecular Hosomi-Sakurai reactions, to set vicinal stereogenic centers
已开发出不对称 Ni 催化的还原交叉偶联来制备对映体富集的烯丙基硅烷。这种对映选择性还原烯基化在温和条件下进行,并表现出良好的官能团耐受性。这里制备的手性烯丙基硅烷经过各种立体定向转化,包括分子内细美-樱井反应,以设置具有优异手性转移的邻位立体中心。
Dearomatization of Indole via Intramolecular [3 + 2] Cycloaddition: Access to the Pentacyclic Skeleton of<i>Strychons</i>Alkaloids
polycyclic indoline-annulated normal to medium-size rings through dearomatization of indole via a tandem 1,2-acyloxy migration/intramolecular [3 + 2] cycloaddition process is described. The pentacyclic skeleton of strychnine could be synthesized via this tandemcycloaddition and a further Mannich reaction. This approach would provide a novel strategy to the synthesis of strychons alkaloids.
Cp*Co(<scp>iii</scp>)-Catalyzed oxidative [5+2] annulation: regioselective synthesis of 2-aminobenzoxepines <i>via</i> C–H/O–H functionalization of 2-vinylphenols with ynamides
作者:Xiang-Lei Han、Xu-Ge Liu、E Lin、Yunyun Chen、Zhuangzhong Chen、Honggen Wang、Qingjiang Li
DOI:10.1039/c8cc06807k
日期:——
A Cp*Co(III)-catalyzed [5+2] C–H annulation reaction of 2-vinylphenols with ynamides was developed. The reaction led to the efficient synthesis of valuable 2-aminobenzoxepines in high regioselectivity. Mild reaction conditions, good functional group tolerance, and moderate to good yields were observed. The synthetic utility was demonstrated by a gram-scale synthesis and further transformations of the