A novel approach to conformationally strained 2,2′-bipyridine thiacrown ethers and their chiral sulfoxides by sequential homo-coupling/DA–rDA reaction of 5,5′-bi-1,2,4-triazine-containing thiamacrocycles
作者:Justyna Ławecka、Zbigniew Karczmarzyk、Ewa Wolińska、Ewa Olender、Danuta Branowska、Andrzej Rykowski
DOI:10.1016/j.tet.2011.02.081
日期:2011.4
The synthesis of conformationally strained 2,2′-bipyridine thiamacrocycles 5, 6, 9, 10 and their chiral sulfoxides 11–14 is elaborated using, (1) homo-coupling of 1,2,4-triazine sulfide 3 with potassium cyanide and (2) Diels–Alder/retro Diels–Alder (DA–rDA) with 2,5-norbornadiene or 1-pyrrolidino-1-cyclopentene as the key steps. The crystal structure determinations of 4–6 and the theoretical calculations
的构象应变2,2'-联吡啶的合成thiamacrocycles 5,6,9,10和它们的手性亚砜11 - 14通过使用(1),同型耦合的1,2,4-三嗪硫化物阐述3与氰化钾和(2)Diels–Alder /复古Diels–Alder(DA–rDA)的关键步骤为2,5-降冰片二烯或1-pyrrolidino-1-cyclopentene。确定了4 – 6的晶体结构,并在DFT / B3LYP / 6-311G ∗∗水平进行了理论计算,从而确定了目标硫杂大环的构象偏爱