Construction of Vicinal Quaternary Carbons via Cu-catalyzed Dearomative Radical Addition
作者:Naoki Tsuchiya、Takashi Nishikata
DOI:10.1246/cl.190247
日期:2019.7.5
In this paper, we confirmed the dearomative addition of tertiary alkyl radicals onto BHT derivatives to form highly congested vicinal quaternary carbons to produce tert-alkylated styrenes in the pr...
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。
Transition metal-free ether coupling and hydroamidation enabling the efficient synthesis of congested heterocycles
The transition-metal-free synthesis of sterically congested ethers and heterocycles via the stereospecific etherification and hydroamidation of α-bromocarboxamides and alkynols.
通过α-溴代羧酰胺和炔醇的立体特异性醚化和羟基化,实现了立体阻碍醚和杂环的过渡金属自由合成。
Trans-selective cyclizations of alpha-bromocarboxamides and <i>E</i>/<i>Z</i>-mixed internal olefins catalyzed by a Fe salt
There are several reports of lactam cyclizations, but most yield less-substituted lactam rings. Therefore, diastereoselective cyclization to yield highly substituted lactams is one of the challenges in this field. We therefore propose a strategy involving the reactions of α-halocarboxamides with E/Z-mixed internal olefins here. An Fe/triphos catalyst system is effective in reactions between α-bromocarboxamides