Synthesis of hindered alkyl aryl ether derivatives (R–O–Ar) remains a huge challenge and highly desirable in organic and medicinal chemistry because extensive substitution on the ether bond prevents the undesired metabolic process and thus avoids rapid degradation in vivo. Herein, we report an unprecedented hindered alkoxylation of picolinamide attached aromatic amines using economic copper salt and
of the reaction pathways of aerobic oxidative coupling of alcohols and amines from amidation to imination was realized for the first time by tuning the Au/Pd ratios in ion-exchangeresin supported Au–Pd alloy catalysts (Au–Pd/resin). Amides were obtained with high yields on Au6Pd/resin while imines were obtained over AuPd4/resin. Various alcohols and amines underwent oxidative coupling smoothly in
Chelation-promoted Efficient C−H/N−H Cross Dehydrogenative Coupling between Picolinamides and Simple Ethers under Copper Catalysis
作者:Qiang Yue、Zhen Xiao、Zhengkun Kuang、Zhengding Su、Qian Zhang、Dong Li
DOI:10.1002/adsc.201701508
日期:2018.3.20
A highly efficient copper‐catalyzed C−H/N−H cross dehydrogenative coupling between picolinamides and simple ethers was developed. The reaction was promoted by the chelation assistance of removable picolinyl group and exhibited excellent TON and TOF number. This method was applicable to both N‐aryl and alkyl picolinamides as well as various cyclic and acyclic ethers with good functional group compatibility
A novel three-component reaction of N-fluoropyridinium salts: a facile approach to imidazo[1,2-a]pyridines
作者:Alexander S. Kiselyov
DOI:10.1016/j.tetlet.2005.04.124
日期:2005.6
The reaction of N-fluoropyridinium triflate with isonitriles in acetonitrile and propionitrile in the presence of NaBH(OAc)3 led to the formation of the corresponding imidazo[1,2-a]pyridines in 44–73% yields. The proposed reaction mechanism involves the intermediate formation of a highly reactive carbene species and apparent reduction of the pyridinium intermediate with NaBH(OAc)3 to yield the targeted
在NaBH(OAc)3存在下,三氟甲磺酸N-氟代吡啶鎓与乙腈和丙腈中的异腈反应,以44-73%的收率形成相应的咪唑并[1,2- a ]吡啶。拟议的反应机理涉及高反应性卡宾物质的中间形成和吡啶鎓中间体与NaBH(OAc)3的明显还原,从而生成目标杂环。