240429-83-8Relevant articles and documents
A new functionalized, chiral disulfide derived from L-cysteine: (R,R)- bis[(3-benzyloxazolan-4-yl)-methane] disulfide as a catalyst in the diethylzinc addition to aldehydes
Braga, Antonio L.,Appelt, Helmoz R.,Schneider, Paulo H.,Silveira, Claudio C.,Wessjohann, Ludger A.
, p. 1733 - 1738 (1999)
A new, easily accessible, chiral disulfide 3 was prepared from L- cysteine in a short synthetic sequence (Scheme 1) and applied successfully as a highly efficient catalyst for the enantioselective addition of diethyl zinc to aromatic and aliphatic aldehydes to afford the product alcohols in up to more than 99% ee. In contrast to the more common amino alcohols used in similar reactions, catalyst 3 does not have a protic hydrogen in the form of a free hydroxy group.
New C2-symmetric chiral disulfide ligands derived from (R)-cysteine
Braga, Antonio L,Appelt, Helmoz R,Schneider, Paulo H,Rodrigues, Oscar E.D,Silveira, Claudio C,Wessjohann, Ludger A
, p. 3291 - 3295 (2007/10/03)
Several sulfur-containing optically active C2-symmetrical ligands have been synthesized from (R)-cysteine and applied successfully as chiral catalysts in the asymmetric addition of diethylzinc to aldehydes. The resulting secondary alcohols could be obtained in good yields and excellent enantiomeric excess.
