2,3,5,6-Tetrakis(methylene)-1,4-cyclohexanediyl (1,2,4,5-tetramethylenebenzene), a disjoint non-Kekule singlet hydrocarbon biradical
作者:James H. Reynolds、Jerome A. Berson、Kristin K. Kumashiro、James C. Duchamp、Kurt W. Zilm、J. C. Scaiano、Alain B. Berinstain、Albino Rubello、Pierre Vogel
DOI:10.1021/ja00071a020
日期:1993.9
has been generated by irradiation of 2,3,5,6-tetramethylene-7-oxonorbornane (5a). It has been observed directly by immobilization in frozen matrices or in polymer films and by time-resolvedspectroscopy following nanosecond later flash photolysis of the ketone precursor 5a. Although the matrix-immobilized irradiated samples containing biradical 4a show a triplet electron spin resonance (ESR) spectrum
The Synthesis of Naphthosultine and Benzodisultines and Their Pyrolysis with Dienophiles: Studies on<i>o</i>-Naphthoquinodimethane and Bis-<i>o</i>-Quinodimethane
作者:An-Tai Wu、Wen-Dar Liu、Wen-Sheng Chung
DOI:10.1002/jccs.200200013
日期:2002.2
aldehyde sulfoxylate) and tetrabutylammonium bromide in DMF gave benzodisultines 17 and 18 in a combined yield of 56%. Sealed tube reactions of benzodisultines 17 and 18 with a series of dienophiles in xylene at 200 °C gave corresponding 1:1 and 1:2 cycloadducts 20–27. The results suggested that thermal extrusion of sulfurdioxide from these sultines led to either o-naphthoquinodimethane 6 (from 8) or bis-o-quinodimethane