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Abstract: Multiply arylated arenes are privileged structural motifs that are significantly used in pharmaceuticals and organic electronic devices. However, due to lack of general methods for installing different substituents and the difficulty to acquire regioselectivity independent of stereo-electronics of existing substituents, this structural diversity has not been fully exploited. To achieve this goal we have to sequentially functionalize arenes which can be easily isolated and it is very challenging to functionalize sequentially since catalysts are unable to differentiate reactivities of reaction sites. Itami et. al. have chosen simple alkenes to introduce different aryl functional groups sequentially which they accomplished by introducing a group that, exerting strong stereo-electronic bias, would allow reactivity differentiation of potential reaction sites. By introducing such groups, fully arylation of Thiophene, Pyridine, furan has been successfully synthesized. The no. of possible substituted arenes (N) from n different substituents is (2n + 2n2 + 4n3 + 3n4 +n6)/12. The synthesis of fully arylated arenes are also synthesized in a programmable manner using C-H activation, cross-coupling and [4+2] cycloaddition reactions.1-2

References-

  1. Itami, K.; Yoshida, J. Chem. Eur. J. 2006, 12, 3966-3974.
  2. Suzuki, S.; Segawa, Y.; Itami, K.; Yamaguchi, J. Nature Chemistry. 2015, 7, 227-233.