Biphenylenes can be easily and efficiently obtained at low temperature by the organolithium-mediated cyclization of halobiphenyls via an aryne intermediate. This synthetic protocol provides an advantage for the direct and controlled functionalization at the C1 position.
A Practical Transition Metal-Free Aryl-Aryl Coupling Method: Arynes as Key Intermediates
作者:Frédéric R. Leroux、Laurence Bonnafoux、Christophe Heiss、Françoise Colobert、Don Antoine Lanfranchi
DOI:10.1002/adsc.200700211
日期:2007.12.10
and, stabilization of the resulting 2-biaryllithium intermediate by in situ transfer of bromine or iodine from the starting material. This straightforward transitionmetal-free access to biaryls allows the preparation of highly valuable halobiaryls on a gram scale in excellent yields. These precursors can be subsequently functionalized by highly regioselective halogen/metal permutations into a vast
Synthesis of Biphenylenes and Their π-Extended Derivatives
作者:Ming-Lun Pan、Yao-Ting Wu
DOI:10.1055/s-0039-1690750
日期:2020.1
A series of biphenylenes and their π-extended derivatives are easily prepared through tert-butyllithium-mediated cyclization of suitable halobiaryls and haloteraryls, respectively. The reactions proceed via the corresponding arynyl intermediates at low temperature (up to –20 °C).