first example of transition-metal-catalyzed C–H activations of 2-phenylisatogens with alkynes and sulfonyl azides has been developed using N-oxide as the directing group. Ru(II)-Catalyzed C–H alkenylation/cyclization and Ir(III)-catalyzed direct C–H sulfamidation proceeded with good yields and excellent functional group tolerance. Importantly, these two transformations provided straightforward routes
A Highly Efficient and Recyclable Pd(Pph<sub>3</sub>)<sub>4</sub>/Peg-400 System for Stille Cross-Coupling Reactions of Organostannanes with Aryl Bromides
作者:Xue Huang、Fang Yao、Ting Wei、Mingzhong Cai
DOI:10.3184/174751917x15045169836226
日期:2017.9
Pd(PPh3)4 in PEG-400 is shown to be a highly efficient catalyst for the Stille cross-coupling reactions of various organotin compounds with arylbromides. The reaction could be conducted at 80 °C using NaOAc as base, yielding a variety of biaryls, alkynes and alkenes in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether and the Pd(PPh3)4/PEG-400
Electrochemically driven, Cp*Ir(III)-catalyzed regioselective annulative couplings of benzoicacids with alkynes have been established herein. The combination of iridium catalyst and electricity not only circumvents the need for stoichiometric amount of chemical oxidant, but also ensures broad reaction compatibility with a wide array of sterically and electronically diverse substrates. This electrochemical
as a powerful strategy for organometallic catalysis, and yet electrocatalytic C−Hactivation is restricted to strongly N‐coordinating directing groups. The first example of electrocatalytic C−Hactivation by weak O‐coordination is presented, in which a versatileruthenium(II) carboxylate catalyst enables electrooxidative C−H/O−H functionalization for alkyne annulations in the absence of metal oxidants;
电催化已被认为是有机金属催化的有力策略,但是电催化CH活化仅限于强N配位的导向基团。给出了通过弱O配位进行电催化C-H活化的第一个例子,其中通用的羧酸钌(II)催化剂可在没有金属氧化剂的情况下实现炔烃环化的电氧化C / H / OH功能化。从而利用可持续的电力作为唯一的氧化剂。机械学的见解为简便的有机金属CH钌钌化和关键钌(0)中间体的有效电化学再氧化提供了有力的支持。
A Practical Synthesis of Biaryls and Aromatic Acetylenes by Stille Coupling in Room-Temperature Ionic Liquids
作者:Wenyan Hao、Zhiwen Xi、Mingzhong Cai
DOI:10.1080/00397911.2011.558233
日期:2012.8.15
cross-coupling reactions of aryl halides with aryl or alkynylstannanes have been achieved under mild conditions in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]), affording the corresponding biaryls and aromatic acetylenes in good yields. Use of this solvent allows for facile recycling of the solvent and catalyst system, which can be used at least five times without loss of activity. GRAPHICAL