1355979-41-7Relevant academic research and scientific papers
Mechanism-Based Enantiodivergence in Manganese Reduction Catalysis: A Chiral Pincer Complex for the Highly Enantioselective Hydroboration of Ketones
Vasilenko, Vladislav,Blasius, Clemens K.,Wadepohl, Hubert,Gade, Lutz H.
, p. 8393 - 8397 (2017)
A manganese alkyl complex containing a chiral bis(oxazolinyl-methylidene)isoindoline pincer ligand is a precatalyst for a catalytic system of unprecedented activity and selectivity in the enantioselective hydroboration of ketones, thus producing preparatively useful chiral alcohols in excellent yields with up to greater than 99 % ee. It is applicable for both aryl alkyl and dialkyl ketone reduction under mild reaction conditions (TOF >450 h?1 at ?40 °C). The earth-abundant base-metal catalyst operates at very low catalyst loadings (as low as 0.1 mol %) and with a high level of functional-group tolerance. There is evidence for the existence of two distinct mechanistic pathways for manganese-catalyzed hydride transfer and their role for enantiocontrol in the selectivity-determining step is presented.
Zinc-Catalyzed Enantioselective Hydrosilylation of Ketones and Imines under Solvent-Free Conditions
Szewczyk, Marcin,Bez?ada, Agata,Mlynarski, Jacek
, p. 3575 - 3579 (2016/12/14)
The zinc acetate promoted asymmetric hydrosilylation of various ketones and imines under solvent-free conditions was examined by using an unprecedented low catalyst loading. Exposure of ketones to 0.05 mol % Zn-based chiral diamine complex in the presence of triethoxysilane afforded enantioenriched alcohols in excellent yields (up to 98 %) and enantioselectivities (up to 97 % ee). This methodology also allowed for the chemoselective 1,2-reduction of α,β-unsaturated ketones and imines.
Highly efficient and convenient asymmetric hydrosilylation of ketones catalyzed with zinc Schiff base complexes
Liu, Shuai,Peng, Jiajian,Yang, Hu,Bai, Ying,Li, Jiayun,Lai, Guoqiao
experimental part, p. 1371 - 1375 (2012/03/08)
Several chiral Schiff base ligands derived from α-amino acids were prepared, and zinc complexes with these chiral Schiff base ligands prepared were tested for the catalytic asymmetric hydrosilylation of ketones, and the results showed that excellent ee va
Enantioselective zinc-catalyzed hydrosilylation of ketones using pybox or pybim ligands
Junge, Kathrin,Moeller, Konstanze,Wendt, Bianca,Das, Shoubhik,Goerdes, Dirk,Thurow, Kerstin,Beller, Matthias
experimental part, p. 314 - 320 (2012/04/18)
The combination of ZnEt2 and chiral pyridinebisoxazoline (pybox) or pyridinebisimidazoline (pybim) ligands catalyzed the asymmetric hydrosilylation of aryl, alkyl, cyclic, heterocyclic, and aliphatic ketones. Under mild conditions, high yields and good enantioselectivities were achieved. ESI measurements allowed for the characterization of the active catalyst. Zincing outside of the pybox: A ZnEt2/pybox catalyst promotes the hydrosilylation of carbonyl compounds under mild conditions to afford high yields and good ee values for a broad range of aryl, alkyl, cyclic, heterocyclic, and aliphatic ketones.
