61925-49-3Relevant articles and documents
Chiral 2-(2-hydroxyaryl)alcohols (HAROLs) with a 1,4-diol scaffold as a new family of ligands and organocatalysts
Dilek, ?mer,Tezeren, Mustafa A.,Tilki, Tahir,Ertürk, Erkan
supporting information, p. 268 - 286 (2017/12/06)
Efficient and modular syntheses of chiral 2-(2-hydroxyaryl)alcohols (HAROLs), novel 1,4-diols carrying one phenolic and one alcohol hydroxyl group, have been developed which led to generation of a small library of structurally diverse HAROLs in enantiomerically pure form. Of the different HAROLs examined, a HAROL based on the indan backbone exhibited the highest activity and enantioselectivity in the 1,2-addition of certain organometallic compounds to aldehydes in the presence of Ti(OiPr)4 (up to 97% y, 88% ee) and performed as a hydrogen-bond donor organocatalyst in the Morita-Baylis-Hillman reaction, promoted by trialkylphosphines.
The synthesis of chiral amino diol tridentate ligands and their enantioselective induction during the addition of diethylzinc to aldehydes
Zhang, An-Lin,Yang, Li-Wen,Yang, Nian-Fa,Liu, Yan-Ling
, p. 289 - 297 (2014/04/03)
A series of C2-symmetric chiral amino diol tridentate ligands 3a-g were prepared from achiral bulky organolithiums, achiral bulky primary amines, and optically active epichlorohydrin (ECH). The prepared C 2-symmetric chiral amino diol tridentate ligands were capable of inducing enantioselectivity in the model reaction of aromatic and aliphatic aldehydes with diethylzinc with an ee of up to 96%. The enantioselectivity can be modulated by adjusting the steric hindrance of the achiral reagents employed in the synthesis of the chiral ligand. The configuration of the addition product depended on the configuration of the amino diol ligands, which can be simply controlled as desired by using the ECH with the desired configuration during the preparation of the ligand.
C2 symmetrical nickel complexes derived from α-amino amides as efficient catalysts for the enantioselective addition of dialkylzinc reagents to aldehydes
Escorihuela, Jorge,Altava, Belen,Burguete, M. Isabel,Luis, Santiago V.
, p. 551 - 558 (2013/07/27)
A series of C2 symmetrical 1:2 Ni:L complexes derived from α-amino amides were studied for the enantioselective addition of dialkylzinc reagents to aldehydes. Different structural elements on the ligands seem to play an important role in determining the observed enantioselectivity. Through optimization of structure and reaction conditions, the best ligand provided secondary alcohols in excellent yields (up to 98%) and enantioselectivity of up to 99% ee for (R)-enantiomer. A transition state model has been proposed to explain the observed enantioselectivities based on computational calculations at the DFT level. Very interestingly, calculations suggest a coordination model of the aldehyde to the metal complex through association of a lone pair of the carbonyl oxygen to the hydrogen atom of an amino group.