Toward a 6pi+6pi zwitterion or a bioinhibitors-related OH-substituted aminoquinone: identification of a key intermediate in their pH controlled synthesis.
Their pH-controlled reactivity places the N,N'-dialkyl-2-amino-5-lithium alcoholate-1,4-benzoquinonemonoimines [C(6)H(2)(NHCH(2)R') (=NCH(2)R')(=O)(OLi)] 7 (R'=tBu) and 8 (R'=p-C(6)H(4)-tBu) at the crossroads of a new versatile strategy for the preparation of two very different classes of substituted quinones. We describe new 2-(N-alkyl)amino-5-hydroxy-1,4-benzoquinones, which are parent molecules to biologically active substituted aminobenzoquinones, for which changes of the N-substituent will become readily possible. The results of the first X-ray structural determination of such compounds ([C(6)H(2)(NHCH(2)tBu)(OH)(=O)(2)] 13) are also reported and we compare the influence of the number of N-substituents of the C(6) ring on the supramolecular networks resulting from self-assembling of 13, zwitterionic N,N'-dineopentyl-2-amino-5-alcoholate-1,4-benzoquinonemonoiminium [C(6)H(2)(=NHCH(2)tBu)(2)(=O)(2)] 9 and N,N',N",N"'-tetraneopentyl-2,5-diamino-1,4-benzoquinone diimine [C(6)H(2)(NHCH(2)tBu)(2)(=NCH(2)tBu)(2)] 15.
Laboratoire de Chimie de Coordination, UMR 7513 CNRS Université Louis Pasteur, 4, rue Blaise Pascal, 67070 Strasbourg Cédex, France. braunst@chimie.u-strasbg.fr
Pierre
P
Braunstein
Olivier
O
Siri
Jean-Philippe
JP
Taquet
Qing-Zheng
QZ
Yang
D016227:Benzoquinones / Q000737:chemistry; D018360:Crystallography, X-Ray; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D011809:Quinones / Q000138:chemical synthesis* / Q000737:chemistry*; D013329:Structure-Activity Relationship
D016227:Benzoquinones; D011809:Quinones