Selective Reduction of Carbonyl Amides: Toward the First Unsymmetrical Bischelating N‐Substituted 1,2‐Diamino‐4,5‐di­amidobenzene

Abstract

Selective reduction of carbonyl amides from key tetraamido intermediate 12 afforded an unprecedented N-substituted 1,2-diamino-4,5-diamidobenzene (13) and/or the first member (14) of a new family of unsymmetrical 12π-electron quinonediimines.

Synthesis and Characterization of Rigid Ditopic N-Heterocyclic Benzobisgermylenes and -stannylenes

“…To test this hypothesis, we have carried out the aerial oxidation of the 1,2,3,4-tetra­(alkylamine)­benzenes 3b , c in THF and obtained the expected N -alkyl-2-(alkylamino)- N′ -alkyl-5-(alkylamino)-1,4-benzoquinonediimines 5b , c as yellow, air-stable solids in essentially quantitative yield (Scheme ). The oxidation of 1,2,3,4-tetra­(alkylamine)­benzenes with loss of the aromatic character in favor of the 1,4-quinoid structure has been reported previously …”

“…The oxidation of 1,2,3,4-tetra(alkylamine)benzenes with loss of the aromatic character in favor of the 1,4-quinoid structure has been reported previously. 21 Reaction of the compounds 5b,c with Sn[N(SiMe 3 ) 2 ] 2 proceeds under mono-transamination at each side of the molecule and formation of the distannylenes 6b,c in yields of 67% and 57%, respectively. The 1 H NMR spectra of the distannylenes 6b,c feature a characteristic resonance for the quinoid CH group 21 at δ 5.52 ppm (5b) and δ 5.14 ppm (5c) and at around δ 0 ppm for the SiMe 3 groups.…”

“…Benzannulated N-heterocyclic germylenes and stannylenes are conveniently obtained by transamination of suitable N , N ′-dialkylated o -phenylenediamines with M­[N­(SiMe 3 ) 2 ] 2 (M = Ge, Sn). , The same protocol can be applied for the synthesis of benzobisgermylenes and benzobisstannylenes of types F2 and F3 provided suitable 1,2,3,4-tetra­(alkylamine)­benzenes are available. We have prepared the asymmetrically substituted 1,2,3,4-tetra­(alkylamine)­benzene 3a (Scheme ) by reaction of the known compound 1 with acetyl chloride to give the 1,2,3,4-tetraamidobenzene 2 . Subsequent reduction of the amido groups with AlH 3 (generated in situ ) gave 3a in good yield.…”

1,3‐Alternate Tetraamido‐Azacalix[4]arenes as Selective Anion Receptors

“…The tetraaza[1.1.1.1]-o,m,o,m-cyclophanes 4a and 4b were prepared in at wo-stepp rocedures tarting from 1 and allowing access to unsymmetrical macrocycles. The reaction between 1,2-diaminobenzenes 2a or 2b [25] and 1 (0.5 equiv) led to the formation of the respective [2 + 1] products 3a and 3b in good yields. Their 1 HNMR spectra ([D 6 ]DMSO)s how ad ownfield NH signal at d = 10.15 and 10.14 ppm for 3a and 3b,r espectively,i na greement with two NH···O 2 Nh ydrogen-bonding interactions that restrict the rotationo ft hese uncyclized precursors and induce their preorganization towards the subsequent macrocyclization.…”

“…Organicsynthesis 1-Benzyl-4-dimethylaminopyridinium bromide, [28] 4-dimethylaminopyridinium bromide, [29] 4,5-diamino-1,2-bis(2,2-dimethylpropionamido)benzene (2b), [25] 4,6,17,19-tetranitro-2,8,15,21-tetraazacalix[4]arene (4c), [24d] and 4,6,16,18-tetranitro-10,12,22,24-tetraamino-2,8,14,20-tetraazacalix[4]arene (6) [26] were prepared and purified according to reported procedures. N 1 ,N 2 -Bis (5-fluoro-2,4-dinitrophenyl)benzene-1,2-diamine( 3a):A solution of 1, 5-difluoro-2,4-dinitrobenzene 1 (2.52 g, 12.35 mmol, 2equiv) in THF (50 mL) was cooled with an ice-water bath before as olution of benzene-1,2-diamine 2a (666 mg, 6.…”