79756-91-5Relevant articles and documents
Hydrazine Hydrate Accelerates Neocuproine–Copper Complex Generation and Utilization in Alkyne Reduction, a Significant Supplement Method for Catalytic Hydrogenation
Chen, Guoliang,He, Xiaoyan,Huang, Gang,Lu, Xiuhong,Wang, Jincheng,Yang, Zhenjiao,Zhang, Yongsheng,Zhang, Zeng
, p. 17696 - 17709 (2021/12/09)
Diimine (HN═NH) is a strong reducing agent, but the efficiency of diimine oxidized from hydrazine hydrate or its derivatives is still not good enough. Herein, we report an in situ neocuproine–copper complex formation method. The redox potential of this complex enable it can serve as an ideal redox catalyst in the synthesis of diimine by oxidation of hydrazine hydrate, and we successfully applied this technique in the reduction of alkynes. This reduction method displays a broad functional group tolerance and substrate adaptability as well as the advantages of safety and high efficiency. Especially, nitro, benzyl, boc, and sulfur containing alkynes can be reduced to the corresponding alkanes directly, which provides a useful complementary method to traditional catalytic hydrogenation. Besides, we applied this method in the preparation of the Alzheimer’s disease drug CT-1812 and studied the mechanism.
Rhodium-Catalyzed Annulation of Phenacyl Ammonium Salts with Propargylic Alcohols via a Sequential Dual C-H and a C-C Bond Activation: Modular Entry to Diverse Isochromenones
Nanubolu, Jagadeesh Babu,Reddy Singam, Maneesh Kumar,Sridhar Reddy, Maddi,Suresh, Vavilapalli,Suri Babu, Undamatla
supporting information, p. 7888 - 7893 (2021/10/25)
Given their omnipresence in natural products and pharmaceuticals, isochromenone congeners are one of the most privileged scaffolds to synthetic chemists. Disclosed herein is a dual (ortho/meta) C-H and C-C activation of phenacyl ammonium salts (acylammonium as traceless directing group) toward annulation with propargylic alcohols to accomplish rapid access for novel isochromenones by means of rhodium catalysis from readily available starting materials. This operationally simple protocol features broad substrate scope and wide functional group tolerance. Importantly, the protocol circumvents the need of any stoichiometric metal oxidants and proceeds under aerobic conditions.
Bimetal Cooperatively Catalyzed Arylalkynylation of Alkynylsilanes
Chen, Xing,Li, Mengke,Liu, Zhipeng,Yang, Can,Xie, Haisheng,Hu, Xinwei,Su, Shi-Jian,Jiang, Huanfeng,Zeng, Wei
supporting information, p. 6724 - 6728 (2021/09/08)
An unprecedented Pd/Rh cooperatively catalyzed arylalkynylation of alkynylsilanes was developed to merge an alkynylidene moiety with benzosilacycle. These silaarenes possess a particular aggregation-induced emission behavior. Mechanistic investigations demonstrate that the relay trimetallic transmetalation plays a pivotal role in governing this transformation.
