1220120-57-9Relevant articles and documents
Rice husk: Introduction of a green, cheap and reusable catalyst for the protection of alcohols, phenols, amines and thiols
Shirini, Farhad,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali,Aliakbar, Ali-Reza
, p. 164 - 170 (2014)
A mild, efficient and eco-friendly protocol for the chemoselective protection of benzylic and primary and less hindered secondary aliphatic alcohols and phenols as trimethylsilyl ethers and different types of amines as N-tert-butylcarbamates is developed using rice husk (RiH) as the catalyst. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols and amines with acetic anhydride. Easy work-up, relatively short reaction times, excellent yields and low cost, availability and reusability of the catalyst are the striking features of this methodology, which can be considered to be one of the best and general methods for the protection of alcohols, phenols, thiols and amines. In addition, the use of a green reagent in the above-mentioned reactions results in a reduction of environmental pollution and of the cost of the applied methods.
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.
Hydrosilane-Promoted Facile Deprotection of tert-Butyl Groups in Esters, Ethers, Carbonates, and Carbamates
Ikeda, Takuya,Zhang, Zhenzhong,Motoyama, Yukihiro
supporting information, p. 673 - 677 (2019/01/04)
Combination of PdCl2 with 1,1,3,3-tetramethyldisiloxane in the presence of activated carbon was found to be an effective catalyst system for the cleavage reaction of C?O bond of O?t-Bu moieties. The present catalytic reaction offers a practical method for the deprotection of tert-butyl esters, tert-butyl ethers, O-Boc, and N-Boc derivatives under mild conditions. The addition of activated carbon in the reaction mixture was proved to be crucial for not only sustaining the catalytic activity but also trapping the palladium species after the reaction. (Figure presented.).
Nanocrystalline titania-based sulfonic acid (TiO2-Pr-SO 3H) as a new, highly efficient and recyclable solid acid catalyst for the N-Boc protection of amines at room temperature
Atghia,Sarvi Beigbaghlou
, p. 42 - 49 (2013/10/01)
Sulfonic acid-functionalized nanoporous titania (TiO2-Pr-SO 3H) was prepared from the reaction of (3-mercaptopropyl) trimethoxysilane and TiO2, then by oxidation of thiols group with hydrogen peroxide. The morphology and acidity of synthesized catalyst was characterized by FT-IR, SEM, TEM, TGA and XRD techniques and Hammett acidity test. The catalytic performance of TiO2-Pr-SO3H was investigated in the N-tert-butoxycarbonylation of amines under solvent-free conditions at room temperature. Our novel method is mild, chemoselective and has the advantages such as heterogeneous catalysis, low cost and the recyclability of the catalyst.
Succinimide sulfonic acid (SuSA): An efficient and recyclable catalyst for the chemoselective N-Boc protection of amines
Shirini, Farhad,Khaligh, Nader Ghaffari
experimental part, p. 631 - 635 (2012/07/03)
Succinimide sulfonic acid (SuSA) as a stable reagent is easily prepared by the reaction of succinimide with neat chlorosulfonic acid. This compound is able to catalyze the chemoselective conversion of amines to their corresponding N-Boc protected derivatives with (Boc)2O. All reactions were performed under mild conditions, giving the desired products in good to high yields. Springer-Verlag 2011.
Sulfonic acid-functionalized ordered nanoporous Na+- montmorillonite (SANM): A novel, efficient and recyclable catalyst for the chemoselective N-Boc protection of amines in solventless media
Shirini, Farhad,Mamaghani, Manouchehr,Atghia, Seyyed Vahid
experimental part, p. 1088 - 1094 (2012/01/15)
Sulfonic acid-functionalized ordered nanoporous Na+- montmorillonite (SANM) was used as an efficient catalyst for N-tert-butoxycarbonylation of amines with di-tert-butyl dicarbonate under solvent-free conditions at room temperature. Various aliphatic, aromatic, heterocyclic amines and aminols were protected as their corresponding mono-carbamates in excellent yields and short reaction times. No competitive side reactions such as isocyanate, urea, and N,N-di-Boc formation were observed. The reported method is mild, chemoselective and has the advantages such as heterogeneous catalysis, low cost and the recyclability of the catalyst.
