26591-84-4Relevant academic research and scientific papers
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.
A water soluble dimeric steroid with catalytic properties. Rate enhancements from hydrophobic binding
Guthrie, J. Peter,Cossar, John,Dawson, Brian A.
, p. 2456 - 2469 (2007/10/02)
Dimeric steroids can be formed by reductive amination of terephthalaldehyde with 3-amino steroids using cyanoborohydride.An amino group in the 11 β-position can be blocked using a formyl group, and this can be removed by acid hydrolysis after dimerization.Trifluoroacetyl is not a suitable blocking group; although it can be removed by acid hydrolysis from monomeric steroids, it was only removed from the dimer under forcing conditions which caused degradation.The dimeric steroid is a catalyst for the hydrolysis of arylpropionate esters with good leaving groups.Acylation is markedly accelerated by hydrophobic binding of the aryl group of the substrate to the steroids.Rate enhancements, relative to imidazole, of up to 5.5 x 102 were obtained, and analysis of the data shows that the potential rate enhancement is 1.1 x 105.The magnitude of the hydrophobic binding is consistent with what was seen with earlier catalysts.Aggregation, even at very low concentrations, was a problem with anionic substrates.
