Conformationally Driven Ru(II)-Catalyzed Multiple <i>ortho</i>-C–H Bond Activation in Diphenylpyrazine Derivatives in Water: Where Is the Limit?
oleh: Sara Hrovat, Miha Drev, Uroš Grošelj, Franc Perdih, Jurij Svete, Bogdan Štefane, Franc Požgan
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2020-04-01 |
Deskripsi
Ru(II)/carboxylate/PPh<sub>3</sub> catalyst system enabled the preparation of highly conjugated pyrazine derivatives in water under microwave irradiation. Both nitrogen atoms efficiently dictated cleavage of the <i>ortho</i>-C–H bonds in both benzene rings of 2,3-diphenylpyrazine substrates through chelation assistance. In conformationally more flexible diphenyldihydropyrazine <b>1,</b> the arylation of four <i>ortho</i>-C–H bonds was possible, while in the aromatic analog <b>2,</b> the triarylation was the limit.