Facile synthesis of 3-substituted imidazo[1,2-<i>a</i>]pyridines through formimidamide chemistry
作者:Rasapalli Sivappa、Vamshikrishna Reddy Sammeta、Yanchang Huang、James A. Golen、Sergey N. Savinov
DOI:10.1039/c9ra05841a
日期:——
A facile entry to 3-aryl/alkenyl/alkynyl substituted imidazo[1,2-a]pyridines (3a–p, 6a–d & 9a–9e) has been developed from readily available benzyl/allyl/propargyl halides and 2-amino pyridines as substrates via formimidamide chemistry that is devoid of caustic or expensive reagents, such as transition metal complexes. Quantum chemical calculations performed to understand the underlying mechanism of
从容易获得的苄基/烯丙基/炔丙基卤化物和2-氨基开发了一种容易进入3-芳基/烯基/炔基取代的咪唑并[1,2- a ]吡啶( 3a–p 、 6a–d和9a–9e )的方法通过甲酰胺化学以吡啶为底物,无需苛性碱或昂贵的试剂,例如过渡金属络合物。为了解转化的潜在机制而进行的量子化学计算揭示了本文报道的系统更倾向于分子内曼尼希型加成而不是周环 1,5-电环化,这使得鲍德温允许 5- exo -trig 环化而不是形式上的反-trig 环化。 Baldwin 5-内切-触发过程。