Abstract
A short, convenient, and scalable protocol for the one-pot synthesis of a series of fluorescent 7,8-dihalo-2,3-diaminophenazines is introduced. The synthetic route is based on the oxidative condensation of 4,5-dihalo-1,2-diaminobenzenes in aqueous conditions. The resulting diaminophenazines could be attractive intermediates for the preparation of polyfunctional phenazines and extended polyheteroacenes. We find that the undesired hydroxylation byproducts, typically obtained in aqueous conditions, are completely suppressed by addition of a stoichiometric amount of acetone during the oxidation step allowing for selective formation of 7,8-dihalo-2,2-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]phenazine derivatives with good to excellent yields. Under reductive conditions, the imidazolidine ring can be hydrolyzed into the desired 7,8-dihalo-2,3-diaminophenazines. Furthermore, we report a selective route under highly reducing conditions to monohydrodeaminate the 2,3-di(methylamino) phenazine derivatives, which allows for further structural variations of these phenazine building blocks. All of these derivatives are luminescent, with measured fluorescence quantum-yields of up to 80% in ethanol for the more rigid structures, highlighting the potential of such materials to provide new fluorophores.
| Original language | English |
|---|---|
| Pages (from-to) | 9881-9888 |
| Number of pages | 8 |
| Journal | Journal of Organic Chemistry |
| Volume | 80 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - Oct 16 2015 |
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ASJC Scopus subject areas
- Organic Chemistry
Cite this
Preparation of Halogenated Fluorescent Diaminophenazine Building Blocks. / Koepf, Matthieu; Lee, Shin Hee; Brennan, Bradley J.; Méndez-Hernández, Dalvin D.; Batista, Victor S.; Brudvig, Gary W; Crabtree, Robert H.
In: Journal of Organic Chemistry, Vol. 80, No. 20, 16.10.2015, p. 9881-9888.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Preparation of Halogenated Fluorescent Diaminophenazine Building Blocks
AU - Koepf, Matthieu
AU - Lee, Shin Hee
AU - Brennan, Bradley J.
AU - Méndez-Hernández, Dalvin D.
AU - Batista, Victor S.
AU - Brudvig, Gary W
AU - Crabtree, Robert H.
PY - 2015/10/16
Y1 - 2015/10/16
N2 - A short, convenient, and scalable protocol for the one-pot synthesis of a series of fluorescent 7,8-dihalo-2,3-diaminophenazines is introduced. The synthetic route is based on the oxidative condensation of 4,5-dihalo-1,2-diaminobenzenes in aqueous conditions. The resulting diaminophenazines could be attractive intermediates for the preparation of polyfunctional phenazines and extended polyheteroacenes. We find that the undesired hydroxylation byproducts, typically obtained in aqueous conditions, are completely suppressed by addition of a stoichiometric amount of acetone during the oxidation step allowing for selective formation of 7,8-dihalo-2,2-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]phenazine derivatives with good to excellent yields. Under reductive conditions, the imidazolidine ring can be hydrolyzed into the desired 7,8-dihalo-2,3-diaminophenazines. Furthermore, we report a selective route under highly reducing conditions to monohydrodeaminate the 2,3-di(methylamino) phenazine derivatives, which allows for further structural variations of these phenazine building blocks. All of these derivatives are luminescent, with measured fluorescence quantum-yields of up to 80% in ethanol for the more rigid structures, highlighting the potential of such materials to provide new fluorophores.
AB - A short, convenient, and scalable protocol for the one-pot synthesis of a series of fluorescent 7,8-dihalo-2,3-diaminophenazines is introduced. The synthetic route is based on the oxidative condensation of 4,5-dihalo-1,2-diaminobenzenes in aqueous conditions. The resulting diaminophenazines could be attractive intermediates for the preparation of polyfunctional phenazines and extended polyheteroacenes. We find that the undesired hydroxylation byproducts, typically obtained in aqueous conditions, are completely suppressed by addition of a stoichiometric amount of acetone during the oxidation step allowing for selective formation of 7,8-dihalo-2,2-dimethyl-2,3-dihydro-1H-imidazo[4,5-b]phenazine derivatives with good to excellent yields. Under reductive conditions, the imidazolidine ring can be hydrolyzed into the desired 7,8-dihalo-2,3-diaminophenazines. Furthermore, we report a selective route under highly reducing conditions to monohydrodeaminate the 2,3-di(methylamino) phenazine derivatives, which allows for further structural variations of these phenazine building blocks. All of these derivatives are luminescent, with measured fluorescence quantum-yields of up to 80% in ethanol for the more rigid structures, highlighting the potential of such materials to provide new fluorophores.
UR - http://www.scopus.com/inward/record.url?scp=84944937172&partnerID=8YFLogxK
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U2 - 10.1021/acs.joc.5b01339
DO - 10.1021/acs.joc.5b01339
M3 - Article
VL - 80
SP - 9881
EP - 9888
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
SN - 0022-3263
IS - 20
ER -