DNMR, DFT and preparative study on the conformation of (Z)-4,5,6,7-tetrahydropyrazolo[1,5-e]benzo[g][1,5]diazonin-8-ones and (Z)-4,5-dihydropyrazolo[1,5-d]benzo[f][1,4]diazocin-7(6H)-ones
作者:Ádám Gyömöre、Zoltán Kovács、Tibor Nagy、Veronika Kudar、András Szabó、Antal Csámpai
DOI:10.1016/j.tet.2008.09.020
日期:2008.11
medium-size ring systems were determined by combined use of DNMR measurements and B3LYP/6-31G(d,p) calculations using the IEFPCM solvent model. One pyrazolobenzodiazonine carrying hydrogen at the C1 position was found to undergo facile ring inversion by a two-step mechanism, while 1-Me and 1-Ph substituents rendered complete rigidity to this ring system. A three-step mechanism was revealed for the ring inversion
分别通过酸酐催化的3,4-二氢-2 H-嘧啶基-和2,3-二氢咪唑并[2,1- a ]邻苯二甲酸酯-萘二甲酸酯的环转化获得的三氮茚腺苷和戊二烯茚的碱催化环扩大,一系列吡唑并[1,5- e ]苯并[ g ] [1,5]重氮素-8-酮和吡唑并[1,5- d ]苯并[ f ] [1,4]重氮素-7(6 H)-获得了一个。通过结合使用IEFPCM溶剂模型进行DNMR测量和B3LYP / 6-31G(d,p)计算,确定对称取代的中型环系统的环反转的替代途径和能量学。发现一种在C1位置携带氢的吡唑并苯并重氮胺通过两步机理进行了容易的环反转,而1-Me和1-Ph取代基对该环系统具有完全的刚性。揭示了三步机理,用于研究的两种吡唑并苯并重氮化合物的环转化,其能量实际上与所研究的C 1取代基(H和Me)不变。N,O的RCM尝试通过Grubbs II催化剂实现的选定刚性模型的α-二烯丙基衍生物可导致脱烯丙基化和