Synthesis, Stability, and X-Ray Crystallographic Structure Analysis of Spiro[1H-azulenium-1,1′-cycloalkane] Ions
作者:Mitsunori Oda、Aya Fukuta (née Sakamoto)、Takanori Kajioka、Takuya Uchiyama、Hitoshi Kainuma、Ryuta Miyatake、Shigeyasu Kuroda
DOI:10.1016/s0040-4020(00)00964-9
日期:2000.12
subsequent hydride abstraction with a trityl salt gave spiro[1H-azulenium-1,1′-cyclopentane and -1,1′-cyclohexane] ions (3 and 4). On the other hand, spiro[1H-azulenium-1,1′-cycloheptane] ion (5) was synthesized from 1-acetylcyclohepta-1,3,5-triene by a sequence involving the Mukaiyama aldol reaction, the Nazarov cyclization, the Shapiro reaction, and hydride abstraction. These cations showed greater
1,6-二氢杂氮烯直接环烷基化,然后用三苯甲基盐提取氢化物,得到螺[1 H -azulenium-1,1'-环戊烷和-1,1'-环己烷]离子(3和4)。另一方面,由1-乙酰基环庚-1,3,5-三烯通过涉及Mukaiyama aldol反应,Nazarov环化的序列合成了螺[1 H -azulenium-1,1'-cycloheptane]离子(5), Shapiro反应和氢化物提取。这些阳离子显示出比三元和四元环同系物更大的动力学稳定性。他们的p K R+值与已知的二取代的对位阳离子相比要大得多,并且处于1位碳原子数的顺序,这表明除π共轭和σ共轭作用外,螺烷基的诱导作用。 ,控制热力学稳定性。还描述了这些阳离子的X射线晶体结构分析。