Reductive Coupling of Acrylates with Ketones and Ketimines by a Nickel-Catalyzed Transfer-Hydrogenative Strategy
作者:Craig S. Buxton、David C. Blakemore、John F. Bower
DOI:10.1002/anie.201707531
日期:2017.10.23
next cycle where it serves as the reductant for C-C bond formation. This strategy represents a conceptually unique approach to transfer-hydrogenative C-C bond formation, thus providing examples of reductive heterocyclizations where hydrogen embedded within an alcohol leaving group facilitates turnover.
丙烯酸苄酯与活化的酮和亚胺在镍催化下偶联,分别生成γ-丁内酯和内酰胺。内酯化/内酰胺化过程中释放的苯甲醇副产物被传递到下一个循环,在其中充当 CC 键形成的还原剂。该策略代表了一种概念上独特的转移氢化CC键形成方法,从而提供了还原性杂环化的例子,其中氢嵌入醇离去基团中促进周转。
Palladium-Catalyzed Aerobic Oxidative Cyclization of <i>N</i>-Aryl Imines: Indole Synthesis from Anilines and Ketones
作者:Ye Wei、Indubhusan Deb、Naohiko Yoshikai
DOI:10.1021/ja3030824
日期:2012.6.6
We report here an operationally simple, palladium-catalyzed cyclization reaction of N-aryl imines, affording indoles via the oxidative linkage of two C-H bonds under mild conditions using molecular oxygen as the sole oxidant. The process allows quick and atom-economical assembly of indole rings from inexpensive and readily available anilines and ketones and tolerates a broad range of functional groups
Borane-Catalyzed Chemoselectivity-Controllable N-Alkylation and <i>ortho</i> C-Alkylation of Unprotected Arylamines Using Benzylic Alcohols
作者:Shan-Shui Meng、Xiaowen Tang、Xiang Luo、Ruibo Wu、Jun-Ling Zhao、Albert S. C. Chan
DOI:10.1021/acscatal.9b03038
日期:2019.9.6
efficient and highlychemoselective alkylation of unprotected arylamines using alcohols catalyzed by B(C6F5)3 has been developed. The reaction gives N-alkylated products and ortho C-alkylated products in different solvents in good chemoselectivities and yields. Control experiments and DFT calculations indicated that the borane underwent alcohol/arylamine exchange to ensure catalytic activity, and a
已经开发出一种空前的方案,用于使用受B(C 6 F 5)3催化的醇对未保护的芳基胺进行高效且高度化学选择性的烷基化反应。该反应在不同溶剂中以良好的化学选择性和收率得到N-烷基化产物和邻C-烷基化产物。控制实验和DFT计算表明,硼烷进行了醇/芳基胺交换以确保催化活性,并提出了涉及碳正离子化的可能机理。
Catalytic Asymmetric α-Iminol Rearrangement: New Chiral Platforms
作者:Xin Zhang、Richard J. Staples、Arnold L Rheingold、William D. Wulff
DOI:10.1021/ja5065685
日期:2014.10.8
A series of 19 different asymmetric catalysts were screened in an effort to identify the first chiral catalyst for the rearrangement of α-hydroxy imines to α-amino ketones involving a 1,2-carbon shift. Although aluminate complexes of VAPOL, VANOL, and 7,7′-tBu2VANOL were quite effective catalysts giving up to 88% ee, the ne plus ultra catalyst for this reaction was found to be a zirconium complex of
筛选了一系列 19 种不同的不对称催化剂,以确定第一个手性催化剂,用于将 α-羟基亚胺重排为 α-氨基酮,涉及 1,2-碳位移。尽管 VAPOL、VANOL 和 7,7'-tBu2VANOL 的铝酸盐配合物是非常有效的催化剂,可提供高达 88% 的 ee,但发现用于该反应的 ne plus 超催化剂是 VANOL 的锆配合物,可提供 97 至 >99% ee 对于大多数检查的底物。该催化剂的 X 射线衍射研究表明,锆以具有三个 VANOL 配体和两个质子化 N-甲基咪唑的均配配合物形式存在。
Organocatalytic Enantioselective Protonation for Photoreduction of Activated Ketones and Ketimines Induced by Visible Light
The first catalyticasymmetric photoreduction of 1,2‐diketones and α‐keto ketimines under visible light irradiation is reported. A transition‐metal‐free synergistic catalysis platform harnessing dicyanopyrazine‐derived chromophore (DPZ) as the photoredox catalyst and a non‐covalent chiral organocatalyst is effective for these transformations. With the flexible use of a chiral Brønsted acid or base in