Design, Synthesis, and Structural Analysis of Influenza Neuraminidase Inhibitors Containing Pyrrolidine Cores
摘要:
The discovery of (+/-)-(2S,3R,4R)-2-(trifluoroacetamido)methyl-3-amino-1-(N ' -ethyl-N ' -isopropylcarbamyl)pyrrolidine-4-earboxylic acid (A-192558, 20e) as a potent inhibitor of influenza neuraminidase (NA) is described. Efficient syntheses of two core structures, cis-3-(allyloxy-carbonyl)amino-1-(9 ' -fluorenylmethoxycarbonyl)pyrrolidine-4-carboxylic acid (7) and tert-butyl (+/-)(2S, 3R,4R)-2-aminomethyl-3-bis(tert-butyloxycarbonyl) amino-1-(N ' -ethyl-N ' -isopropylcarbamyl)pyrrolidine-4-carboxylate (18b), were developed. Starting with these core structures and using available structural information of the NA active site as the guide, analogues were synthesized in both the tri- and tetrasubstituted pyrrolidine series by means of high-throughput parallel synthesis in solid or solution phase for expeditious SAR. These studies accelerated the identification of(+/-)-(2S,3R,4R)-2-(trifluoroacetamido)methyl-3-amino-1-(N-ethyl-N-isopropylcarbamyl)pyrrolidine-4-carboxylate (20e, A-192558) as the most potent NA inhibitor in this series (IC50 = 0.2 muM against NA A and 8 muM against NA B). The X-ray crystallographic structure of A-192558 bound to NA revealed the predicted interaction of the carboxylic group with the positively charged pocket (Arg118, Arg292, Arg371) and interaction of the trifluoro-acetamino residue with the hydrophobic pocket (Ile222, Trp178) of the enzyme active site. Surprisingly, the ethyl and isopropyl groups of the urea functionality induced a conformational change of Glu276, turning the Glu276/Glu277 hydrophilic pocket, which normally accommodates the triglycerol side chain of substrate sialic acid, into an induced hydrophobic pocket.
Can Heteroarenes/Arenes Be Hydrogenated Over Catalytic Pd/C Under Ambient Conditions?
作者:Nao Tanaka、Toyonobu Usuki
DOI:10.1002/ejoc.202000695
日期:2020.9.14
Pd/C‐mediated dearomatic hydrogenation underambientconditions such as balloon pressure and room temperature can be a powerful tool for constructing alicyclic skeletons. Density functional theory calculations have been performed to confirm the mechanistic aspects and the utility of the established methodology has been demonstrated by donepezil synthesis.
Disclosed herein are secondary amine compounds that inhibit tRNA synthetase. The compounds of the invention are useful in inhibiting tRNA synthetase in Gram-negative bacteria and are useful in killing Gram-negative bacteria. The secondary amine compounds of the invention are also useful in the treatment of tuberculosis.
A simple and efficient method has been developed for the synthesis of N-allylthioureas from allylic bromides in one-pot by using a supported reagents system, KSCN/SiO2–RNH3OAc/Al2O3, in which allyl bromide reacts first with KSCN/SiO2 and the product, allyl isothiocyanate, reacts with RNH3OAc/Al2O3 to give the final product, N-allylthiourea, in good yield.
通过使用支持的试剂系统KSCN / SiO 2 -RNH 3 OAc / Al 2 O 3,由一锅法从烯丙基溴中合成N-烯丙基硫脲的简单有效方法已被开发,其中烯丙基溴首先与KSCN / SiO 2和产物异硫氰酸烯丙酯与RNH 3 OAc / Al 2 O 3反应,以高收率得到最终产物N-烯丙基硫脲。
Studies on the Chemistry and Reactivity of α-Substituted Ketones in Isonitrile-Based Multicomponent Reactions
作者:Lijun Fan、Ashley M. Adams、Jason G. Polisar、Bruce Ganem
DOI:10.1021/jo8019708
日期:2008.12.19
Using the Passerini and Ugi reactions as representative tests, the utility of several alpha-substituted ketones R-CO-CH(2)-X (X = sulfonyloxy, acyloxy, azido, halo, hydroxy, and sulfonyl) in isonitrile-based multicomponent reactions was explored. In a relative rate study (R = PhCH(2)CH(2)), each of the alpha-substituted ketones underwent Passerinicondensation more rapidly than the parent ketone. Short
Synthese und Reaktionsverhalten 4-phenylsubstituierter Isochinuclidine
作者:Woldemar Schneider、Gottfried Krombholz
DOI:10.1002/ardp.19803130603
日期:——
Verschiedene Synthesewege, die zu den 2‐Alkyl‐4‐phenylisochinuclidinen 14 und 15, zu den 3.4‐Diphenylisochinuclidinen 22–24 sowie zum 6‐Oxo‐4‐phenyl‐3‐isochinuclidon (43) führen, werden beschrieben. Die Struktur der bei der sauren Hydrolyse von 7‐Phenyl‐1.4‐dioxaspiro‐[4.5]decan‐7‐carbonsäureamid (36) entstehenden Produkte wird durch spektroskopische Methoden sowie durch Abbaureaktionen aufgeklärt