Combined Rhodium-Catalyzed Carbon-Hydrogen Activation and β-Carbon Elimination to access Eight-Membered Rings
作者:Damien Crépin、James Dawick、Christophe Aïssa
DOI:10.1002/anie.200904527
日期:2010.1.12
Enlarge! CH bond activation and β‐carbon elimination are combined in a net intramolecular hydroacylation of alkylidenecyclobutanes and alkylideneazetidines in the presence of rhodium catalysts, affording eight‐membered‐ring compounds in high yield (see scheme). This study demonstrates the possibility of exploiting the strain energy of azetidines through β‐carbon elimination in new transition‐metal‐catalyzed
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。
ANDERSON, WAYNE K.;KINDER, FREDERICK R. (JR), J. HETEROCYCL. CHEM., 27,(1990) N, C. 975-979