Unusually Facile Syntheses of Diquat (6,7-Dihydrodipyrido[1,2-a:2′,1′-c]pyrazinediium) and Related Cations

Abstract

A new and versatile method for the synthesis of cyclic diquaternary cations under mild conditions is described. Treatment of various a-diimines with 1,2-bis(triflyloxy)ethane in diethyl ether, chloroform, or dichloromethane at room temperature affords diquats in yields of up to 98%.

Synthesis, Optical Properties, and DNA Interaction of New Diquats Based on Triazolopyridines and Triazoloquinolines

“…The herbicide activity was found to be directly related to its capacity to produce oxidative stress in cells by generating Reactive Oxygen Species (ROS) . In addition, compound 1 has shown relevance as an ion‐pair charge‐transfer complex and a supramolecular modulator . Similar structures have been reported in the literature by employing different alkylating agents or even more complex dinitrogen compounds .…”

“…[1] Compound 1 was first reported in 1958 by R. L. Jones et al as ap owerful herbicide agent. [5] In ad-dition,c ompound 1 has shown relevancea sa ni on-pair charge-transfer complex [6] and as upramolecular modulator. [5] In ad-dition,c ompound 1 has shown relevancea sa ni on-pair charge-transfer complex [6] and as upramolecular modulator.…”

1,2,7,8-Tetramethyl-4,5-dihydro-3a,5a-diazapyrene ditriflate

“…Salt (II) was synthesized as reported previously (Coe, Curati & Fitzgerald, 2006). Crystals suitable for single-crystal X-ray diffraction were obtained by slow diffusion of diethyl ether vapour into an acetone solution of (II) at 295 K. All H atoms were included in calculated positions, with C-H = 0.95 (CH), 0.99 (CH 2 ) and 0.98 Å (CH 3 ); U iso (H) values were fixed at 1.2U eq (C) or 1.5U eq (methyl C).…”

3,6-Dimethyl-4,5-dihydro-3a,5a-diazapyrene ditriflate

“…Salts (I) and (II) were synthesized as reported previously (Coe, Curati & Fitzgerald, 2006). Crystals suitable for single-crystal X-ray diffraction measurements were obtained by slow diffusion of diethyl ether vapour into acetone solutions at 295 K. All H atoms were included in calculated positions, with C-H = 0.95 (CH), 0.99 (CH 2 ) and 0.98 Å (CH 3 ).…”

“…In recent years, the attractive redox properties of diquats have led to other uses as electron acceptors in light-harvesting chromophore-quencher systems (Ryu et al, 1992;Klumpp et al, 1999;Kim et al, 2003Kim et al, , 2005 and in ion-pair charge-transfer complexes (Nunn et al, 1994;Hofbauer et al, 1996;Unamuno et al, 1998;Vitoria et al, 2002). Our studies directed at using diquats in novel metalbased chromophore-quencher arrays have afforded an unusually facile method for the synthesis of such compounds, including salts (I) and (II) (Coe, Curati & Fitzgerald, 2006). The structure of salt (II), 1,2,7,8-tetramethyl-4,5-dihydro-3a,5a-diazapyrene ditriflate, is presented in the following paper (Coe, Fitzgerald & Raftery, 2006).…”