From Allenes to Tetracenes: A Synthetic and Structural Study of Silyl- and Halo-Allenes and Their Dimers
作者:Emilie V. Banide、Bevin C. Molloy、Yannick Ortin、Helge Müller-Bunz、Michael J. McGlinchey
DOI:10.1002/ejoc.200600905
日期:2007.6
and hydrolysis of 13d yields 3,3-(biphenyl-2,2′-diyl)-1-(trimethylsilyl)allene (20), which forms successively the head-to-tail dimer 1-(9-fluorenylidene)-4-(trimethylsilyl)-2-[(trimethylsilyl)methylene]spiro[cyclobutane-3,9′-[9H]fluorene] (21) and the tail-to-tail dimer trans-3,4-bis(trimethylsilyl)-1,2-di(fluorenylidene)cyclobutane (23) both of which exhibit long (ca. 1.6 A) C(3)–C(4) bonds. Treatment
Reinvestigation on Thermal Cycloaddition of 1-Aryl-2-(9-fluorenylidene)-1-haloethylenes
作者:Masahiro Minabe、Masaaki Yoshida、Seiji Saito、Keisuke Tobita、Takashi Toda
DOI:10.1246/bcsj.61.2067
日期:1988.6
The thermal treatment of 1-bromo-2-(9-fluorenylidene)-1-phenylethylene afforded three different types of [2+2]cycloaddition products. The 1-tolyl homolog showed similar trends, but the chloro analog gave only two types. These results suggest that reactions of the rigid and bulky allenes take place through a 2,2′-biradical giving head-to-head, head-to-tail, and tail-to-tail adducts through the expected processes.