A combined structural and computational investigation of aminobenzylnaphthol compounds derived from the Betti reaction using valine methyl ester

Abstract

The crystal structures of racemic and (S, S)-aminobenzylnaphthols, obtained with a Betti reaction between 2-naphthol, aryl aldehydes and valine methyl ester, were investigated using X-ray diffraction measurements. The molecular shapes...

(S,S)-2-(((Hydroxynaphth-1-yl)(4′-nitrophenyl)methyl)amino)-3-methylbutanoic Acid Methyl Ester

“…In the crude reaction mixture, we observed two signals for that hydrogen, the first lying at 5.68 ppm (predominant, and subsequently isolated), and the other one at 5.93 ppm. According to our previous considerations, the (S,S)-configuration can be attributed to the aminobenzylnaphthol having the benzyl hydrogen signal at 5.68 ppm, thus confirming the trend in which every time we undertake a Betti reaction with an (S)-amine, (S,S)aminobenzylnaphthols are regularly obtained [6,[8][9][10].…”

“…In our past screening of different aryl aldehydes, we tested 4-fluoro-and 4-chlorobenzal dehyde in reactions with 2-naphthol and (S)-valine methyl ester [8,9]. The desired (S,S)aminobenzylnaphthols were obtained in good yield and without any particular stereochemical issue, even when higher temperatures (60 • C) were applied [8,9].…”

“…In the absence of a crystal suitable for the X-ray diffraction experiment [9,10], the (S,S) configuration can be attributed to H(1)-NMR considerations. This procedure was employed by us and was found to be reliable [6,8] when it was compared with the absolute configurations obtained via X-ray diffraction experiments [9,10].…”

“…This exploration might lead us to reconsider our assumptions about how we interact with the environment, and how we value sharks, as well as to reexamine the legal and policy frameworks that guide our decision-making processes. In alignment with emerging ocean scholarship and comparative Rights of Nature cases, references to the Ocean and Nature will be capitalized to emphasize their intrinsic value in place of valuing the environment as a resource [9,28,29]. Building upon the ethics, applications, and analyses of Rights of Nature well-established in the literature, this paper adopts an interdisciplinary perspective in demonstrating the urgency for shark protection at national and global scales in light of the applicability of Rights of Nature as a holistic…”

1-[(1S)-(4-Fluorophenyl)-((1′S)-1′-naphthalen-1-yl-ethylamino)-methyl]-naphthalen-2-trifluoromethanesulfonate

“…Pyridine (40 µL, 0.5 mmol) and 1-[(1S)-(4-Fluorophenyl)-((1′S)-1′-naphthalen-1-ylethylamino)-methyl]-naphthalen-2-ol 1 [8] (0.21 g, 0.5 mmol) were dissolved in 8 mL of dichloromethane. Trifluoromethanesulfonic anhydride (84 µL, 0.5 mmol) was added to Since the reaction does not involve the stereogenic centres, and the conditions that caused their scrambling in similar compounds are absent [12,13], it is reasonable to believe that the obtained triflate species 2 maintained the same (S,S)-configuration. As a further point of interest, as previously reported [14,15], the functionalisation of the naphthol hydroxyl moiety always has relevant consequences on the crystal structures, because it inhibits the formation of the intramolecular OH•••N hydrogen bond and causes a new rearrangement of the aryl group in the molecule [14,15].…”