Discovery of Oxygen α-Nucleophilic Addition to α,β-Unsaturated Amides Catalyzed by Redox-Neutral Organic Photoreductant
作者:Zi-Hong Luan、Jian-Ping Qu、Yan-Biao Kang
DOI:10.1021/jacs.0c10707
日期:2020.12.16
addition) products. On the contrary, the formation of α-hydroxyl or alkoxyl amides through conjugateaddition needs an α,β-inverse addition. Nevertheless, a regio-inversed nucleophilic α-addition of oxygen-centered nucleophiles to α,β-unsaturated carbonyl compounds still remains less explored because of the electronic mismatch. In this research, we discovered the first α-specific nucleophilic addition
Nucleophilic substitutions, including SN1 and SN2, are classical and reliable reactions, but a serious drawback is their intolerance for both bulky nucleophiles and chiral tertiary alkyl electrophiles for the synthesis of a chiral quaternary carbon center. An SRN1 reaction via a radical species is another conventional method used to carry out substitutionreactions of bulky nucleophiles and alkyl halides
包括S N 1和S N 2在内的亲核取代是经典且可靠的反应,但一个严重的缺点是它们对于庞大的亲核试剂和手性叔烷基亲电子试剂都不容忍合成手性季碳中心。一个S RN通过自由基物质进行的1反应是用于进行大体积亲核试剂和烷基卤化物的取代反应的另一种常规方法,但是不能使用手性叔烷基亲电试剂。因此,尚未充分研究使用手性叔烷基亲电试剂和大体积亲核试剂的立体特异性亲核取代反应。在本文中,我们描述了叔烷基醇与非手性或手性α-溴代羧酰胺作为叔烷基源的反应,以形成在氧原子上具有立体保留的两个不同叔烷基的拥挤醚化合物。
Silver‐Promoted Fluorination Reactions of α‐Bromoamides
Silver‐promoted C−F bond formation in α‐bromoamides by using AgF under mild conditions is reported. This simple method enables access to tertiary, secondary, and primary alkyl fluorides involving biomolecular scaffolds. This transformation is applicable to primary and secondary amides and shows broad functional‐group tolerance. Kinetics experiments revealed that the reaction rate increased in the order