Selective hydration of electron-rich aryl-alkynes by a Schrock-type molybdenum alkylidene catalyst
摘要:
We present herein the regioselective hydration of electron-rich aryl-alkynes in presence of a Schrock-type molybdenum alkylidene catalyst. The structures of the obtained ketones were confirmed by NMR spectroscopy and HRMS as well as by single-crystal X-ray diffraction. We found out that in our conditions the hydration reaction is efficient only for aryl-alkynes and their reactivity is highly dependent on the electronic nature of the substituents on the aryl group.
Cobalt‐Catalyzed Intermolecular [2+2] Cycloaddition between Alkynes and Allenes
作者:Wei Ding、Naohiko Yoshikai
DOI:10.1002/anie.201813283
日期:2019.2.18
An intermolecular [2+2] cycloaddition reaction between an alkyne and an allene is reported. In the presence of a cobalt(I)/diphosphine catalyst, a near equimolar mixture of the alkyne and allene is converted into a 3‐alkylidenecyclobutene derivative in good yield with high regioselectivity. The reaction tolerates a variety of internal alkynes and mono‐ or disubstituted allenes bearing various functional
Silver-Mediated Oxidative C–H/P–H Functionalization: An Efficient Route for the Synthesis of Benzo[<i>b</i>]phosphole Oxides
作者:Yun-Rong Chen、Wei-Liang Duan
DOI:10.1021/ja407373g
日期:2013.11.13
A Ag-mediated C-H/P-H functionalization reaction of arylphosphine oxides with internal alkynes was described for the direct preparation of benzo[b]phosphole oxides with a high yield. An unusual aryl migration on the P-atom derived from a C-P bond cleavage and a new C-P bond formation was also observed and demonstrated to proceed via the radical process.
描述了芳基氧化膦与内部炔烃的 Ag 介导的 CH/PH 官能化反应,用于以高产率直接制备苯并 [b] 磷氧化物。还观察到来自 CP 键断裂和新 CP 键形成的 P 原子上不寻常的芳基迁移,并证明是通过自由基过程进行的。
Direct Synthesis of 1-Arylprop-1-ynes with Calcium Carbide as an Acetylene Source
作者:Lei Gao、Zheng Li
DOI:10.1055/s-0037-1610718
日期:2019.8
A simple method is described for the synthesis of 1-arylprop-1-ynes directly from aromatic aldehyde p-tosylhydrazones by using calcium carbide as an acetylene source. The salient features of this protocol are its use of a readily available and easily handled source of acetylene, its operational simplicity, its high yield, and its broad substrate scope.
Benzophosphole construction was achieved through the AgI‐mediated dehydrogenative annulation of phenylphosphine oxides with internal alkynes in a process involving CC and CPbondformation. A wide range of asymmetrical phenylacetylenes could be employed and the reactions proceeded with perfect regioselectivity. Moreover, the annulation could be conducted even at room temperature when a MnIII promoter
A regioselectivity switch in Pd-catalyzed hydroallylation of alkynes
作者:Ding-Wei Ji、Yan-Cheng Hu、Hao Zheng、Chao-Yang Zhao、Qing-An Chen、Vy M. Dong
DOI:10.1039/c9sc01527b
日期:——
Through rational evaluation of ligands and promoters, the reactivity of a key Pd(ii) species towards transmetalation or β-H elimination is manipulated.