Urethane protected derivatives of 1-guanylpyrazole for the mild and efficient preparation of guanidines
摘要:
Bis-urethane protected derivatives of 1-guanylpyrazole were prepared and found to readily react with relatively unreactive amines at room temperature to produce bis-protected guanidines in good yields. Simultaneous removal of both protecting groups from these products efficiently produced monosubstituted guanidines.
Catalytic Synthesis of Cyclic Guanidines via Hydrogen Atom Transfer and Radical-Polar Crossover
作者:Shunya Ohuchi、Hiroki Koyama、Hiroki Shigehisa
DOI:10.1021/acscatal.0c05359
日期:2021.1.15
because of a lack of efficientpreparation strategies and low yield. Herein, a catalytic synthetic method for cyclic guanidines was developed via transition-metal hydrogen atom transfer and radical-polar crossover. This mild and functional-group-tolerant process enabled the cyclization of alkenyl guanidines bearing common protective groups, such as Cbz and Boc groups. This powerful method provided not only