1580471-57-3Relevant academic research and scientific papers
Concise and scalable asymmetric synthesis of 5-(1-amino-2,2,2- trifluoroethyl)thiazolo[3,2-b][1,2,4]triazoles
Mei, Haibo,Xiong, Yiwen,Xie, Chen,Soloshonok, Vadim A.,Han, Jianlin,Pan, Yi
, p. 2108 - 2113 (2014/03/21)
This study describes asymmetric Mannich-type additions between C-5 lithiated thiazolo[3,2-b][1,2,4]triazoles and enantiomerically pure (S S)-N-tert-butanesulfinyl-(3,3,3)-trifluoroacetaldimine. Under the optimized conditions, these reactions proceed with good (up to 78%) chemical yields and virtually complete (98 : 2 to >99 : 1 dr) diastereoselectivity. The same stereochemical outcome was obtained using 1.05 g scale of the starting (3,3,3)-trifluoroacetaldimine. The method developed in this work provides concise and generalized access to thiazolo[3,2-b][1,2,4]triazoles containing a chiral (trifluoro)ethylamine group.
Large-scale Mannich-type reactions of (SS)-N-tert- butanesulfinyl-(3,3,3)-trifluoroacetaldimine with C-nucleophiles
Xie, Chen,Mei, Haibo,Wu, Lingmin,Han, Jianlin,Soloshonok, Vadim A.,Pan, Yi
supporting information, p. 67 - 75 (2014/07/22)
Here we describe the first attempts to scale up five addition reactions between (SS)-N-tert-butanesulfinyl-(3,3,3)-trifluoroacetaldimine 6 with C-nucleophiles derived from ketones (two examples), glycine Schiff base and heterocycles (two examples). In all cases studied, the observed stereochemical outcome of the scaled up (5.0-25.0 mmol) reactions was lower as compared with the original 0.5 mmol scale. However, the observed worsening of yields and diastereoselectivity was not identical and depended on the reaction conditions and reaction mechanisms. In general, scaling up of the reactions conducted at ambient temperatures presented no problems while the low-temperature (-78 °C) processes would require special equipment to provide strict maintenance of the reaction temperature to obtain the desirable outcome. Importantly, using procedures described here, series of biologically relevant compounds containing 2,2,2-trifluoro-1-(amino)ethyl [CF3CH(NH2)-] pharmacophore unit can be prepared in enantiomerically pure form on up to 5 g scale, allowing their systematic biological studies.
