An efficient sequence for the preparation of small secondary amine hydrochloride salts for focused library generation without need for distillation or chromatographic purification
摘要:
Collections of small secondary amines for compound library generation can be efficiently prepared by amide reduction using BH(3)-THF or Red-Al followed by brief methanolysis, trapping with di-tert-butyl dicarbonate, and deprotection with 4M HCl in dioxane. The sequence requires no chromatography or distillation and provides multi-gram quantities of pure HCl salts in a short time.
Synthesis of α-CF3 carbonylcompounds has been recognized to be difficult up to now because the polarization of CF3δ−-Iδ+ is opposite to that of CH3δ+-Iδ−, and this makes it difficult to introduce CF3+ unit to enolates. We recently reported an effective α-trifluoromethylation of ketones by using Et2Zn with Rh catalyst, but the mechanism has not fully been cleared. Now, we carried out the detailed mechanistic
yl-γ,δ-unsaturated carbonyl compounds based on the Claisen rearrangement is reported. Fluorinated olefins were used as building blocks supplying fluorine atoms. As a result, fluorinated esters and alcohols were also obtained. They are a valuable material for subsequent transformations. The methodology presented in this work could be applied to a wide range of compounds as a valuable tool to construct