An auxiliary-aided Pd-catalyzed highly diastereoselective double C–H activation and direct bis-arylation of methylene C(sp³)–H bonds of cyclobutanecarboxamides and the syntheses of several novel trisubstituted cyclobutanecarboxamide scaffolds having an all-cis stereochemistry are reported. Extensive screening of various auxiliaries and reaction conditions was performed to firmly establish the optimized reaction conditions required for effecting the mono- or double C–H arylation of cyclobutanecarboxamides. The auxiliary-attached cyclobutanecarboxamides 15a, 15g, and 15h, prepared from the auxiliaries such as, 8-aminoquinoline, 2-(methylthio)aniline, and N′,N′-dimethylethane-1,2-diamine were found to undergo an efficient direct bis-arylation. The Pd-catalyzed arylation reaction of N-(quinolin-8-yl)cyclobutanecarboxamide 15a with one equivalent or more of aryl iodides, afforded the corresponding bis-arylated cyclobutanecarboxamides 16a–y. Nevertheless, the Pd-catalyzed arylation of 15a with just 0.5 equiv of the aryl iodides 13a, 13b, 13e, and 13m, selectively gave the corresponding monoarylated cyclobutanecarboxamides 17a–17d. The Pd-catalyzed arylation of 15g or 15h with one equivalent or more of aryl iodides afforded the bis-arylated cyclobutanecarboxamides 19a–19c and 21a–21m, respectively. However, the Pd-catalyzed arylations of compounds 15g or 15h with just 0.5 equiv of aryl iodides were ineffective. The stereochemistry of compounds obtained in this work was unambiguously assigned from the X-ray structures of representative products.

中文翻译：

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环丁烷的通过双C-H活化直二芳基化：辅助计算机辅助立体选择性钯催化的访问三取代环丁烷支架有三个相邻的立体中心和ALL- CIS立体化学

辅助辅助Pd催化的高度非对映双C-H活化和亚甲基（SP的C直接双-芳基化³）-H cyclobutanecarboxamides的键和若干新颖的合成三取代环丁烷支架具有清一色顺式立体化学被报告。对各种助剂和反应条件进行了广泛的筛选，以牢固地建立实现环丁烷甲酰胺的单或双CH芳基化所需的优化反应条件。由助剂如8-氨基喹啉，2-（甲硫基）苯胺和N '，N制备的辅助连接的环丁烷甲酰胺15a，15g和15h发现'-二甲基乙烷-1,2-二胺经历了有效的直接双芳基化。N-（喹啉-8-基）环丁烷甲酰胺15a与一当量或更多的芳基碘化物经Pd催化的芳基化反应，得到相应的双芳基化环丁烷甲酰胺16a - y。尽管如此，的Pd催化的芳基化部15a与仅0.5当量的芳基碘的13A，13B，13E，和13米，选择性地得到相应的monoarylated cyclobutanecarboxamides 17A - 17D。Pd催化的芳基化为15g或15h用一个或多个当量的芳基碘化物分别制得双芳基化的环丁烷甲酰胺19a - 19c和21a - 21m。然而，仅用0.5当量的芳基碘化物的化合物15g或15h的Pd催化的芳基化是无效的。从代表性产品的X射线结构明确分配了这项工作中获得的化合物的立体化学。