30249-30-0Relevant articles and documents
High-Throughput Screening of Reductive Amination Reactions Using Desorption Electrospray Ionization Mass Spectrometry
Cooks, R. Graham,Ferreira, Christina R.,Li, Yangjie,Logsdon, David L.,Paschoal Sobreira, Tiago Jose,Thompson, David H.
supporting information, p. 1647 - 1657 (2020/10/26)
This study describes the latest generation of a high-throughput screening system that is capable of screening thousands of organic reactions in a single day. This system combines a liquid handling robot with desorption electrospray ionization (DESI) mass spectrometry (MS) for a rapid reaction mixture preparation, accelerated synthesis, and automated MS analysis. A total of 3840 unique reductive amination reactions were screened to demonstrate the throughputs that are capable with the system. Products, byproducts, and intermediates were all monitored in full-scan mass spectra, generating a complete view of the reaction progress. Tandem mass spectrometry experiments were conducted to verify the identity of the products formed. The amine and electrophile reactivity trends represented in the data match what is expected from theory, indicating that the system accurately models the reaction performance. The DESI results correlated well with those generated using more traditional mass spectrometry techniques like liquid chromatography-mass spectrometry, validating the data generated by the system.
Heterogeneous Ni catalysts for N-alkylation of amines with alcohols
Shimizu, Ken-Ichi,Imaiida, Naomichi,Kon, Kenichi,Hakim Siddiki,Satsuma, Atsushi
, p. 998 - 1005 (2013/06/27)
Nickel nanoparticles loaded onto various supports (Ni/MOx) have been prepared and studied for the N-alkylation of amines with alcohols. Among the catalysts, Ni/θ-Al2O3 prepared by in situ H 2-reduction of NiO/θ-Al2O3 shows the highest activity, and it acts as reusable heterogeneous catalyst for the alkylation of anilines and aliphatic amines with various alcohols (benzyl and aliphatic alcohols) under additive free conditions. Primary amines are converted into secondary amines and secondary amines into tertiary amines. For the reaction of aniline with an aliphatic alcohol the catalyst shows higher turnover number (TON) than precious metal-based state-of-the-art catalysts. Mechanistic studies suggest that the reaction proceeds through a hydrogen-borrowing mechanism. The activity of Ni catalysts depends on the nature of support materials; acid-base bifunctional supports give higher activity than basic or acidic supports, indicating that acid-base sites on supports are necessary. The presence of basic (pyridine) or acidic (acetic acid) additive in the solution decreased the activity of Ni/θ-Al2O3, which suggests the cooperation of the acid-base site of θ-Al2O3. For a series of Ni/θ-Al2O3 catalysts with different particle size, the turnover frequency (TOF) per surface Ni increases with decreasing Ni mean particle size, indicating that low-coordinated Ni species and/or metal-support interface are active sites. From these results, we propose that the active site for this reaction is metal-support interface, where low-coordinated Ni0 atoms are adjacent to the acid-base sites of alumina.
Reductive removal of sulfonyl groups: Cleavage of sulfonamides and sulfonates by alkali metal combined with crown ether
Ohsawa,Takagaki,Ikehara,et al.
, p. 3178 - 3186 (2007/10/02)
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