Trifluoromethylphenylcarbenes. Carbene-Carbene Interconversion on the Singlet Energy Surface and Rearrangement to Trifluorobenzocyclobutene, Trifluorostyrene, and Trifluoromethylfulvenallenes
作者:Rodney J. Blanch、Curt Wentrup
DOI:10.1071/ch14097
日期:——
carbenes are observed in the ESR spectra. Flash vacuum thermolysis of the diazirene 1 at 500°C afforded a mixture of bis(trifluoromethyl)heptafulvalenes 11, bis(trifluoromethyl)stilbenes 12, and bis(trifluoromethyl)anthracenes 13, and the presence of their likely precursor(s), trifluoromethylcycloheptatetraene(s), was confirmed by a peak at 1830 cm–1 in the Ar matrix IR spectrum. In addition, at 700°C,
四个异构体α-,邻- ,间- ,和对由相应的3-苯基-3- trifluoromethyldiazirene的光解产生-trifluoromethylphenylcarbenes 1或四个异构体trifluoromethylphenyldiazomethanes 2和4 - 6。所述四个相应的三线态trifluoromethylphenylcarbenes 3和7 - 9通过电子自旋共振进行观察(ESR)光谱学在Ar中在矩阵14 K的α-和邻-卡宾3和7以及邻-和对-卡宾当由短波长光解(350nm)产生时,图7和9在系统间穿越到三重态之前部分地互换。三重态不进行进一步的Carbene-Carbene互变。假定通过间三氟甲基苯基卡宾8进行相互转化。当长波光解(> 450 nm)生成邻位和对位碳宾烯时,在ESR光谱中观察到了离散的,非互变的三重态碳烯。在500°C下对二氮杂戊烯1进行快速真空热