Unclicking of thioureas: Base catalyzed elimination of anilines and isothiocyanates from thioureas
作者:Matea Vlatković、Ben L. Feringa
DOI:10.1016/j.tet.2019.02.035
日期:2019.4
Bisaromatic thioureas are widely used in e.g. asymmetric organocatalysis and considered to be robust compounds. Herein we show, in strong contrast to common notion, that thioureas dissociate to amines and isothiocyanates in a base catalyzed reaction under mild conditions. This ‘unclicking’ process can occur in the presence of weak organic bases even at moderate temperatures. The influence of the substituents
双芳族硫脲被广泛用于例如不对称有机催化中,并且被认为是坚固的化合物。与常见的观点强烈相反,在此我们表明,在温和的条件下,在碱催化的反应中,硫脲离解为胺和异硫氰酸酯。即使在中等温度下,在弱有机碱的存在下也会发生这种“无点击”过程。还显示了在硫脲的芳香环上的取代基对这种解click过程的区域选择性的影响。