Hydroxy-1-aminoindans and Derivatives:  Preparation, Stability, and Reactivity

Abstract

The chemical stability and reactivity of hydroxy-1-aminoindans and their N-propargyl derivatives are strongly affected by the position of the OH group and its orientation relative to that of the amino moiety. Thus, the 4- and 6-OH regioisomers were found to be stable, while the 5-OH analogues were found to be inherently unstable as the free bases. The latter, having a para orientation between the OH and the amino moieties, could be isolated only as their hydrochloride salts. 7-Hydroxy-1-aminoindans and 7-hydroxy-1-propargylaminoindans represent an intermediate case; while sufficiently stable even as free bases, they exhibit, under certain experimental conditions, unexpected reactivity. The instability of the 5- and 7-hydroxy-aminoindans is attributed to their facile conversion to the corresponding, reactive quinone methide (QM) intermediates. The o-QM obtained from 7-hydroxy-aminoindans was successfully trapped with ethyl vinyl ether via a Diels-Alder reaction to give tricyclic acetals 32a,b.

Synthesis and Carbonic Anhydrase Inhibitory Effects of Novel Sulfamides Derived from 1‐Aminoindanes and Anilines

“…On the other hand, amine 14 was synthesized according to the procedure described in the literature . The reactions of 1 equivalent amines 12 – 14 and 1.2 equivalent benzyl alcohol (BnOH) with chlorosulfonyl isocyanate (CSI) yielded new sulfamoyl carbamates 15 – 17 .…”

Kinetic Effects of Increased Proton Transfer Distance on Proton-Coupled Oxidations of Phenol-Amines

“…25 However, 2 was successfully prepared via reductive amination of 7-hydoxy-1-indanone 25 followed by alkylation in tert -butanol/H 2 SO 4( aq ) in the presence of urea. 26 The resulting salt was deprotonated to the neutral amine, 2 , which has been characterized by IR, NMR, and mass spectrometry (see Experimental Section).…”

Iridium‐Catalyzed Asymmetric Hydrogenation of Unfunctionalized Exocyclic C=C Bonds

“…According to a patent, this intermediate can be further transformed into a series of insecticides (Scheme a). An additional transformation was possible in the presence of MeNH 3 Cl and NaBH 3 CN, the product of which (obtained in 86 % yield) can be used for treatment of synucleinopathies (Scheme b) …”

“…Other types of phosphine-oxazoline ligands, such as tBu-PHOX (L5), planar-chiral mono-tBu-Ru-PHOX( L6), and (aS)-tBu-Binaph-PHOX (L7)w erea lso screened. Unfortunately,t hey only yielded trace amountso fp roduct (entries [13][14][15]. To our delight,i f 1 mLo fA cOH was used as an additive in the reaction, the hydrogenation proceeded smoothly and provided the best over-all performance with full conversion and 93 % ee (entry 16).…”

“…An additional transformationw as possible in the presence of MeNH 3 Cl and NaBH 3 CN, the product of which (obtained in 86 %y ield) can be used for treatment of synucleinopathies (Scheme 3b). [15] In conclusion, we developed an efficient asymmetrich ydrogenationo fu nfunctionalized exocyclic olefins. By using an Ir catalystw ith an axially flexible chiral phosphine-oxazoline Scheme2.Deuterium-labeling study and asymmetric hydrogenation of unfunctionalized endocyclic olefins.…”