α-Fluoroenamides, potent rigid fluorinated bioisosters of ureas, have been synthesized by a highly regio- and stereo-selective hydrofluorination of ynamides in anhydrous HF. This reaction provides the first general entry to α-fluoroenamides and can easily be applied to a wide range of substrates.
With Et3N·3HF as the fluorination reagent, (IPr)CuF-catalyzed α-site regiocontrolled trans-hydrofluorination of ynamides has been achieved, affording (Z)-α-fluoroenamides in moderate to excellent yields. It was interesting to note that the regioselectivity of the reaction is reversed to that observed in the (Ph3P)3CuF-catalyzed hydrofluorination of ynamides. Additionally, a variety of different ynamides
and electronic properties that partially mirror those of ureas, therefore demonstrating that the hydrofluorination of ynamides provides a general, straightforward, and user-friendly approach to bioisosteres of ureas, potent building blocks for biological studies and medicinal chemistry.
(Radio)fluoroclick Reaction Enabled by a Hydrogen-Bonding Cluster
作者:Xiaojun Zeng、Junling Li、Chin K. Ng、Gerald B. Hammond、Bo Xu
DOI:10.1002/anie.201711341
日期:2018.3.5
We have developed a widely applicable nucleophilic (radio)fluoroclick reaction of ynamides with readily available and easy‐to‐handle KF(18F). The reactions exhibited high functional‐group tolerance and needed only an ambient atmosphere. This 18F addition to C−C unsaturated bonds proceeded with extraordinarily high radiochemical yields.
我们开发了一种广泛适用的 ynamides 与易于获得且易于处理的 KF( 18 F) 的亲核(放射性)氟点击反应。该反应表现出高官能团耐受性,并且仅需要环境气氛。这种18 F 加成到 CC 不饱和键上的过程具有极高的放射化学产率。