New C2-symmetry diols accumulating one stereogenic axis and two stereogenic centers

A New Chirally Organized Trifluoromethylanthrylmethanol Derivative and Its Application as Chiral Solvating Agent

“…For this purpose we considered the reduction of trifluoromethylaryldiketones using catecholborane as reductor and (S)-methyl oxazaborolidine as chiral auxiliary, CBS-reduction, [28,29] and also Noyori's asymmetric transfer hydrogenation, [30,31] both reduction processes already employed satisfactorily in our research group. [13,26] Unfortunately, all our attempts to reduce 3 with Noyori's catalyst, RuCl(p-cymene)[(R,R)-Ts-DPEN], in isopropanol, sodium formiate in water, [33] or in a two phase system, [34,35] were unsuccessful and the starting material was always recovered. We even studied the reduction of other simpler trifluoromethylanthracenylketones, like 1, 2, and the simplest trifluoromethyanthrylketone, but the results were also negative in all cases.…”

“…Therefore, we focused our efforts in accumulating both, axial and central chirality, in our new goals. We have already published one of the simplest ways to incorporate axial chirality, namely to change the aromatic subunit from an anthracene ring to a binaphthyl group . Herein, we report on the synthesis and the enantiodifferentiation behaviour of 1,1′‐(((10,10’‐(1,1′‐binaphthalene)‐2,2′‐diylbis(oxy))bis(methylene))bis(anthracene‐10,9‐diyl))bis(2,2,2‐trifluoroethanol), 4 , a new CSA which incorporates both, axial and central chirality, and additionally presents a remarkable increase of its aromatic surface.…”

“…We have already published one of the simplest ways to incorporate axial chirality, namely to change the aromatic subunit from an anthracene ring to a binaphthyl group. [13] Herein, we report on the synthesis and the enantiodifferentiation behaviour of 1,1'-(((10,10'-(1,1'-binaphthalene)-2,2'-diylbis(oxy))bis(methylene))bis (anthracene-10,9-diyl))bis(2,2,2-trifluoroethanol), 4, a new CSA which incorporates both, axial and central chirality, and additionally presents a remarkable increase of its aromatic surface. This new compound contains two anthracene subunits [14][15][16][17] and a (1,1'-binaphtalene)-2,2'-diol (BINOL) moiety, which has also been used previously as a CSA itself.…”

Design of Phosphinic Acid Catalysts with the Closest Stereogenicity at the α-Position: Synthesis and Application of α-Stereogenic Perfluoroalkyl Phosphinic Acid Catalysts

“…Plausible reaction mechanism of stereoselective addition/cyclization reaction is as shown in Scheme . After methyl phosphinate becomes an active trivalent chemical species due to tautomerism, nucleophilic addition proceeds to a carbonyl group activated by the Lewis acid, and subsequently, intramolecular nucleophilic addition proceeds. The key to the high diastereoselectivity of the reaction sequence is the high level of recognition of the Re and Si faces of the carbonyl group in the nucleophilic addition of methyl phosphinate in inter- and then intramolecular additions.…”