A Rhodium-Catalyzed C−H Activation/Cycloisomerization Tandem
作者:Christophe Aïssa、Alois Fürstner
DOI:10.1021/ja0746316
日期:2007.12.1
A reaction cascade comprising a rhodium-catalyzed C-H activation, a subsequent hydrometalation of an alkylidene cyclopropane in vicinity, regioselective C-C bond activation of the flanking cyclopropane ring, followed by reductive elimination of the resulting metallacycle, opens a new entry into functionalized cycloheptene derivatives. This crossover of C-H activation and higher order cycloaddition
反应级联反应包括铑催化的 CH 活化,随后附近亚烷基环丙烷的加氢金属化,侧翼环丙烷环的区域选择性 CC 键活化,然后还原消除所得金属环,打开了功能化环庚烯衍生物的新入口。CH 活化和更高级环加成的这种交叉已经以两种不同的形式进行,要么使用带有侧乙烯基吡啶部分的亚烷基环丙烷,要么使用悬垂的醛基作为触发器。该反应耐受各种官能团,使反应位点的手性中心 α 不受影响,并以优异的立体选择性进行。标记实验支持所提出的解释观察到的净环异构化过程的机制。
Lewis Acid-Mediated Formation of 1,3-Disubstituted Spiro[cyclopropane-1,2′-indanes]: The Activating Effect of the Cyclopropane Walsh Orbital
By virtue of its alkylidenecyclopropane moiety, 2-(cyclopropylidenemethyl)benzaldehyde reacts with a range of amines and thiols under Lewis acid catalysis. These reactions yield 1,3-bis(arylamino) and 1,3-bis(arylthio and alkylthio)indanes, respectively, which are spirolinked to the cyclopropane ring at carbon 2. The reaction mechanism, and the peculiar contribution of the cyclopropane ring, have been
A Selective Rh<sup>I</sup>
-Catalyzed Substrate-Controlled C−C Bond Activation of Benzyl Sulfonamide/Alcohol-Tethered Alkylidenecyclopropanes
作者:Kai Chen、Jia-Xin Liu、Xiang-Ying Tang、Min Shi
DOI:10.1002/chem.201602366
日期:2016.8.8
Benzyl sulfonamide/alcohol‐tethered alkylidenecyclopropanes undergo a rhodium‐catalyzed and substrate‐controlled selective C−C bond activation, producing three types of common organic structural units: benzo[c]azepine/oxepines, dihydronaphthalen‐1‐amines, and conjugated dienes. Epoxidation and aromatization of these products to construct two useful compounds have also been achieved.