213267-92-6Relevant articles and documents
Deciphering the mechanism behind efficient enantioselective ethylation with thiazolidine-based amino alcohols
Cacho, Vanessa R. G.,Costa, Dora C. S.,Murtinho, Dina,Nunes, Sandra C. C.,Pais, Alberto A. C. C.,Silva Serra, M. Elisa,Tavares, Nélia C. T.
, (2022/01/08)
Taking advantage of the opposite chirality of two privileged starting materials, l-cysteine and d-penicillamine, a wide range of thiazolidine-based amino alcohols was synthesized. l-Cysteine derivatives were more efficient chiral inductors than the d-peni
Chiral zinc amidate catalyzed additions of diethylzinc to aldehydes
Zhang, Jinxia,Li, Shasha,Zheng, Xinxin,Li, Hongjie,Jiao, Peng
supporting information, p. 1913 - 1917 (2019/06/24)
A series of bifunctional spiro ligands bearing “carboxamide–phosphine oxide” groups and ethylzinc carboxamidates from these ligands as catalysts for Et2Zn additions to aldehydes were reported. Excellent yields were obtained with moderate ee′s in Et2Zn additions to benzaldehyde derivatives, implying effectiveness of our newly designed catalytic structures as well as mediocre stereocontrol by these chiral ligands. Possible transition states were suggested based on the crystal structures of two ligands.
Chiral thiazolidines in the enantioselective ethylation of aldehydes: An experimental and computational study
Tavares, Nélia C.T.,Neves, César T.,Milne, Bruce F.,Murtinho, Dina,Pais, Alberto A.C.C.,Serra, M. Elisa Silva
, p. 1 - 10 (2018/10/20)
A library of new chiral thiazolidines was prepared starting from L-cysteine and D-penicillamine in a simple, one-step procedure. 2-Arylthiazolidines were obtained, as diastereoisomeric mixtures, with good yields and in short reaction times, through a new and greener procedure, using microwave irradiation. Their use as chiral ligands in the enantioselective ethylation of aromatic aldehydes was studied and optimized, originating good to excellent conversions and ee up to 94% in 6 h. A series of heteroaromatic and aliphatic substrates were also enantioselectively ethylated with success, with ee up to 77%. The distinct opposite chirality in L-cysteine and D-penicillamine makes the use of these ligands an interesting approach for obtaining both the (S) and (R) enantiomers of the chiral alcohols, compounds with potential applications in the area of fine chemistry. NMR studies were carried out using a diastereoisomeric mixture of thiazolidines, allowing the identification of the most stable structure. Computational studies confirmed this result and also gave important insight into the species involved in the catalytic cycle of the enantioselective alkylation.