Ruthenium-Catalyzed Urea Synthesis by N-H Activation of Amines
Ruthenium-Catalyzed Urea Synthesis by N-H Activation of Amines
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DOI：
10.1021/acs.inorgchem.7b00962
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发表时间：
2017-06-19
影响因子：
4.6
通讯作者：
Gunanathan, Chidambaram
中科院分区：
文献类型：
--
作者：
Krishnakumar, Varadhan;Chatterjee, Basujit;Gunanathan, Chidambaram
证明了钌钳配合物通过“胺-酰胺”金属-配体合作激活胺的 N-H 键。原位观察到 N,N-二甲基甲酰胺 (DMF) 的催化甲酰基 C-H 活化，导致 CO 和二甲胺的形成。这种新的键激活模式的范围扩展到使用 DMF 作为一氧化碳 (CO) 替代物从胺合成尿素衍生物。该催化方案允许合成简单且功能化的尿素衍生物并释放氢气，无需任何化学计量的活化试剂，并避免直接使用致命的CO。催化羰基化在低温下发生以提供甲酰胺；分离出甲酰胺中间体。连续添加不同的胺提供不对称的脲化合物。建议该反应通过胺的 N-H 活化、随后从 DMF 插入 CO 并释放氢气来进行。
Activation of the N-H bond of amines by a ruthenium pincer complex operating via "amine-amide" metal-ligand cooperation is demonstrated. Catalytic formyl C-H activation of N,N-dimethylformamide (DMF) is observed in situ, which resulted in the formation of CO and dimethylamine. The scope of this new mode of bond activation is extended to the synthesis of urea derivatives from amines using DMF as a carbon monoxide (CO) surrogate. This catalytic protocol allows the synthesis of simple and functionalized urea derivatives with liberation of hydrogen, devoid of any stoichiometric activating reagents, and avoids the direct use of fatal CO. The catalytic carbonylation occurred at low temperature to provide the formamide; a formamide intermediate was isolated. The consecutive addition of different amines provided unsymmetrical urea compounds. The reactions are proposed to proceed via N-H activation of amines followed by CO insertion from DMF and with liberation of dihydrogen.