C−H Methylation of Iminoamido Heterocycles with Sulfur Ylides**
作者:Prithwish Ghosh、Na Yeon Kwon、Saegun Kim、Sangil Han、Suk Hun Lee、Won An、Neeraj Kumar Mishra、Soo Bong Han、In Su Kim
DOI:10.1002/anie.202010958
日期:2021.1.4
The direct methylation of N‐heterocycles is an important transformation for the advancement of pharmaceuticals, agrochemicals, functional materials, and other chemical entities. Herein, the unprecedented C(sp2)‐H methylation of iminoamido heterocycles as nucleoside base analogues is described. Notably, trimethylsulfoxonium salt was employed as a methylating agent under aqueous conditions. A wide substrate
A straightforward palladium-catalyzed oxidative C-3 arylation of quinoxalin-2(1H)-ones with arylboronicacids is reported. This protocol is compatible with a wide range of functional groups and allows construction of various biologically important quinoxalin-2(1H)-one backbones.
A direct C–H alkylation of quinoxalinones at the C‐3 position with sodiumalkylsulfinates and phenyliodine(III) dicarboxylates has been developed under catalyst‐free conditions. A series of 3‐alkylquinoxalinones were afforded in moderate to excellent yields in this protocol, which offers a practical and efficient access to biologically interesting 3‐alkylquinoxalin‐2(1H)‐one derivatives.
Transition-metal-free, three-component trifluoromethylative heteroarylation of unactivated alkenes: Efficient access to β-trifluoromethylated quinoxalinones and preliminary antifungal evaluation against Magnaporthe grisea
作者:Zhuoxian Shao、Shaoyi Zhang、Yihan Chen、Yun-Lin Liu、Ri-Yuan Tang、Zhaodong Li
DOI:10.1016/j.tet.2020.131199
日期:2020.5
unactivated alkenes is presented by employing CF3SO2Na and quinoxalin-2(1H)-ones as coupling partners and PhI(OAc)2 as oxidant. This three-component radical domino reaction allows an efficient synthesis of valuable β-trifluoromethyl alkyl quinoxalinones derivatives in a single step in moderate to excellent yields under mild conditions. Mechanistic studies indicated the cascade radical addition pathway controlled
在此,通过使用CF 3 SO 2 Na和喹喔啉-2(1 H)-ones作为偶合配偶体和PhI(OAc)2作为氧化剂,给出了未活化烯烃的无过渡金属的三氟甲基化杂芳基化作用。这种三组分自由基多米诺骨牌反应可有效合成有价值的β-三氟甲基烷基喹喔啉酮衍生物,在温和的条件下,一步一步即可获得中等至优异的收率。机理研究表明,级联自由基加成途径受自由基极性控制。这种由三部分组成的策略可轻松提供具有合成和生物学意义的三氟甲基和喹喔啉酮类骨架,这已通过首次对稻瘟病菌的初步抗菌评估得到了证明。
Discrimination in the Solid-State Photodimerization of 1-Methyl-5,6-diphenylpyrazin-2-one
作者:Menahem Kaftory、Vitaly Shteiman、Tali Lavy、John R. Scheffer、Jie Yang、Volker Enkelmann
DOI:10.1002/ejoc.200400350
日期:2005.3
1-Methyl- and 1-ethyl-5,6-diphenylpyrazin-2-one crystallize in two modifications, one of which is light-stable and the other light-sensitive. The light-sensitive modification is known to undergo photodimerization in the solid state. This polymorph crystallizes in the monoclinic space group P21 with two crystallographically independent molecules in the asymmetric unit. The molecules are packed in stacks