1,2-diamino-1,2-diphenylethane

Racemic and meso 2,3-diphenyldihydrodiazepines have been prepared starting from racemic and meso 1,2-diamino-1,2-diphenylethane (77TL2709). 

A key step in the total synthesis of the marine metabolite (—)-solanopyrone D (161) is the enantioselective organocatalytic intramolecular Diels-Alder reaction of the trienal (158) to the decalin aldehyde (160) in the presence of the imidazolidinone catalyst (159) (Scheme 45).187 Protonated 1,2-diamino-1,2-diphenylethane has been... 

Evaporation of the mother liquor and treatment of the residue under similar experimental conditions afforded ( )-(—)-34 in a yield of 57% with an optical purity of 62%. Optically active threo-1,2-diamino-1,2-diphenylethane was also an effective diamine for the optical resolution of racemic 34 that was obtained in a yield of 78% with an optical purity of 92% [70]. As previously described, the optical resolution of racemic trans-1,2-cyclohexanediol could be performed under similar experimental conditions [27]. Notably, this procedure was found effective also for the optical resolution of hydroxy oximes. Thus, when equimolar amounts of racemic ( )-l,2-diphenyl-2-(hydroxyimino)ethanol (50) and (R,R)-29 were added to benzene and crystallized, (7 )-(—)-( )-50 was recovered in a yield of 56 % based on the enantiomer in the racemate (Scheme 24) [27]. 

Diamino- 1,2-diphenylethane (112) and l,2-dichloro-l,2-bis (p-tolylimino) ethane (113) gave 2,3-diphenyl-5,6-di-p-toluidino-2,3-dihydropyrazine (114) (EtjN, PhMe, 20°C, until thin-layer chromatography (TLC) shows no dichloro synthon 80%) also analogues.979... 

Alternate Name (5,5)-DPEN (5,5 )-1,2-diphenyl-1,2-ethanedi-amine (5,5)-1,2-diamino-1,2-diphenylethane (5,5)-stilbenedi-amine (5,5)-a,p-diaminodihydrostilbene. 

Corey and co-workers developed the highly enantioselective allylboron reagent 198 [127], whose chiral 1,2-diamino-1,2-diphenylethane (stein) auxiliary [254] serves as the source of asymmetry. In an extension of this methodology, Williams et al. have demonstrated the utility of the bromoborane 332 for the preparation of synthetically complex allylborane reagents [255] and have applied this methodology in two natural product syntheses [256, 257] (see below). 

Organocatalyzed asymmetric Diels-Alder reaction of cyclopentadiene and a,p-unsaturated aldehyde by protonated 1,2-diamino-1,2-diphenylethane (47, DPEN) was reported by Ha et al., Scheme 3.14 [26],... 

This methodology has also been employed for the preparation of tetradentate ligands by exchanging the primary amines for C2-symmetric primary diamines (eq 4). For example, from (/ ,/ -1,2-diamino-1,2-diphenylethane, diastereomeric ligand B was obtained in 84% yield. These aromatic amines are sufficiently reactive to open the aziridine ring. Due to steric hindrance, no further reaction of the secondary amine moieties with (5)-A -trifluoromethylsulfonyl-2-isopropylaziridine was observed. This tetradentate ligand was inferior to his(sulfonamides) as catalyst... 

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