过渡金属催化的单分子片段偶联 (UFC) 定义为通过分子(如 CO 和 CO 2)的挤出以及随后剩余片段的重组形成新化学键的过程。在此,我们报道了一种新的 UFC 反应,该反应涉及钯催化从酰胺中消除异氰酸酯片段,形成碳-碳和碳-杂原子键。通过 X 射线晶体学表征了与催化反应相关的有机金属中间体。这种 UFC 反应能够实现酰胺官能团的后期转化,从而使酰胺能够用作可转换的导向或保护基团。
An efficient one‐pot N‐alkylation of benzimidazole and benzotriazole from carbonyl compounds and tosylhydrazide has been accomplished via copper powder‐catalyzed N—H bond insertion affording N‐alkylated products in good yields. The reaction can tolerate a wide range of carbonyl compounds, such as aryl, alkyl, heterocyclic and α,β‐unsaturated ketones, and aldehydes.
Sustainable Palladium-Catalyzed Tsuji–Trost Reactions Enabled by Aqueous Micellar Catalysis
作者:Nicholas R. Lee、Farbod A. Moghadam、Felipe C. Braga、Daniel J. Lippincott、Bingchun Zhu、Fabrice Gallou、Bruce H. Lipshutz
DOI:10.1021/acs.orglett.0c01329
日期:2020.7.2
reactions, can be run under micellarcatalysis conditions featuring not only chemistry in water but also numerous combinations of reaction partners that require low levels of palladium, typically on the order of 1000 ppm (0.1 mol %). These couplings are further characterized by especially mild conditions, leading to a number of cases not previously reported in an aqueous micellar medium. Inclusion of diverse
Asymmetric intermolecular allylic C–H amination of alkenes with aliphatic amines
作者:Kelvin Pak Shing Cheung、Jian Fang、Kallol Mukherjee、Andranik Mihranyan、Vladimir Gevorgyan
DOI:10.1126/science.abq1274
日期:2022.12.16
Aliphatic allylic amines are found in a great variety of complex and biorelevant molecules. The direct allylic C–H amination of alkenes serves as the most straightforward method toward these motifs. However, use of widely available internal alkenes with aliphatic amines in this transformation remains a synthetic challenge. In particular, palladium catalysis faces the twin challenges of inefficient
Page 11037. The required annotation for compound 6j in Table 4 was inadvertently missing in our original manuscript. Footnote c has been added to 6j to note that a higher reaction temperature and a longer reaction time were required for this specific substrate, as given below. This information is also included in the revised Supporting Information. The Supporting Information is available free of charge