Wang Xiang, Hu Huayou, Li Qiuyun, Zhi Sanjun, Ji Cheng-Long, Hao Wen-Juan, Jiang Bo
School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huaian 223300, China.
Faculty of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
J Org Chem. 2025 Feb 14;90(6):2156-2162. doi: 10.1021/acs.joc.4c02385. Epub 2025 Feb 5.
A base-promoted regioselective formal [3 + 2] annulation of pyridinium ylides with bromoalkynes is reported, producing a series of substituent-diverse indolizines in generally good yields. A mild KCO-promoted three-component formal [3 + 2] cyclization of pyridinium ylides and bromoalkynes at a 2:1 molar ratio delivered C2-acylmethylated indolizines, whereas C2-brominated indolizines were generated starting from pyridinium ylides bearing strong electron-withdrawing groups at the pyridinium unit by using 2,2,6,6-tetramethyl-1-piperidinyloxy as a dehydrogenating reagent. The current synthetic methodology offers a controllable and modular approach to access indolizines with different substitution patterns, featuring a wide substrate scope, good functional group compatibility, and complete regioselectivity without the demand of any transition-metal catalysts.
报道了吡啶叶立德与溴代炔烃在碱促进下的区域选择性形式[3 + 2]环化反应，以良好的产率生成了一系列具有不同取代基的中氮茚。温和的碳酸钾促进吡啶叶立德与溴代炔烃以2:1的摩尔比进行三组分形式[3 + 2]环化反应，得到C2-酰基甲基化中氮茚，而通过使用2,2,6,6-四甲基-1-哌啶氧基作为脱氢试剂，从吡啶单元带有强吸电子基团的吡啶叶立德出发，可以生成C2-溴代中氮茚。目前的合成方法提供了一种可控的模块化方法来合成具有不同取代模式的中氮茚，具有广泛的底物范围、良好的官能团兼容性和完全的区域选择性，且无需任何过渡金属催化剂。
