155727-93-8Relevant articles and documents
Photocatalyzed E→Z Contra-thermodynamic Isomerization of Vinyl Boronates with Binaphthol
Brégent, Thibaud,Bouillon, Jean-Philippe,Poisson, Thomas
supporting information, p. 13966 - 13970 (2021/08/25)
The photocatalytic contra-thermodynamic E→Z isomerization of vinyl boronates by using a binaphthol catalyst is disclosed. The reaction, based on the transient formation of a suitable chromophore with a BINOL derivative as the catalyst, allowed geometrical isomerization in good-to-excellent Z/E ratio and excellent-to-quantitative yields. The mechanism of this E→Z contra-thermodynamic isomerization was studied, and the formation of a transient chromophore species is suggested.
Synthesis of structurally modified atropisomeric biaryl dithiols. Observations on the Newman-Kwart rearrangement
Cossu, Sergio,De Lucchi, Ottorino,Fabbri, Davide,Valle, Giovanni,Painter, Gavin F.,Smith, Robin A.J.
, p. 6073 - 6084 (2007/10/03)
The preparation of a number of biaryldithiols from biaryldiols is discussed. A key reaction is the Newman-Kwart thermorearrangement of bisthiocarbamates and crucial variables of temperature and reaction time have been identified. Alternative approaches to 3,3'-disubstituted dithiols via ortho metallation are presented. The benefit of using such disubstituted compounds is illustrated with representative examples of the stereochemical features of the derived carbanions in reactions with prochiral electrophiles.
Preparation of Enantiomerically Pure 1,1'-Binaphthalene-2,2'-diol and 1,1'-Binaphthalene-2,2'-dithiol
Fabbri, Davide,Delogu, Giovanna,Lucchi, Ottorino De
, p. 1748 - 1750 (2007/10/02)
A practical preparation of enantiomerically pure 1,1'-binaphthalene-2,2'-diol (1) and 1,1'-binaphthalene-2,2'-dithiol (2) is reported.Enantiopure 2 is obtained from enantiopure 1 via Newman-Kwart rearrangement of the thiocarbamoyl derivative 5 under controlled reaction conditions.The enantiopure starting diol 1 was obtained by a simple and inexpensive method engaging condensation of thiophosphoryl chloride and (S)-(-)-α-methylbenzylamine in pyridine and reaction of the resulting phosphoramidate 3 with racemic binaphthol 1 to give quantitatively a 1:1 mixture of diasteroisomers 4 that were cleanly separated by a single recrystallization from a chloroform-ethanol mixture in very high yield.The procedures can be scaled up easily.