PhSeBr mediated hydroxylative oxidative dearomatization of naphthols – an open air facile one-pot synthesis of ketols

Abstract

GHOSH, M. K.; ROUT, N.; GIRI, S.; RSC Adv. 6 (2016) 32, 26886-26894, http://dx.doi.org/10.1039/C6RA00036C ; Dep. Chem., Natl. Inst. Technol., Rourkela 769 008, Odisha, India; Eng.) -M. Tismer 30-043

Selenium‐NMR Spectroscopy in Organic Synthesis: From Structural Characterization Toward New Investigations

“…Another electrophilic selenium species employed to promote oxidation reaction is PhSeBr. In 2016, Sarkar and co‐workers demonstrated the applicability of this selenium reagent in the oxidative‐dearomatization of β‐naphthol in a metal‐free synthetic methodology [146] . Using two equivalents of PhSeBr in a mixture of THF:H 2 O at room temperature, it was possible to obtain a great substrate scope with higher yields (Scheme 32).…”

“…In 2016, Sarkar and coworkers demonstrated the applicability of this selenium reagent in the oxidative-dearomatization of β-naphthol in a metal-free synthetic methodology. [146] Using two equivalents of PhSeBr in a mixture of THF:H 2 O at room temperature, it was possible to obtain a great substrate scope with higher yields (Scheme 32). The reaction mixture was evaluated by 77 SeÀ { 1 H} NMR experiment, and a new signal at δ Se = 1116.0 ppm was detected, together with PhSeSePh (δ Se = 452.0 ppm), and the PhSeBr starting material (δ Se = 870.0 ppm).…”

Regioselective C(sp2)−C(sp3) Oxidative Bond Cleavage of 1‐(1‐Hydroxyalkyl) naphthalen‐2‐ols: First Synthesis of 1‐Azido‐halo‐naphthalene‐2(1H)‐ones

“…[9] Recently, the azides have also been used as azidation agents to alkynols. [10] With our continued interest on dearomatization reactions [11] and particularly azidative dearomatization, [12] we were attracted towards the 1-azido-1-bromonaphthalen-2(1H)-one (4) molecule which resembles a synthetically important molecule and had no reports in the cited literature (Figure 1).…”

Phenyl trimethyl ammonium tribromide mediated robust one-pot synthesis of spiro-oxacycles – an economic route – stereoselective synthesis of oxaspirohexacyclodieneones

“…R f = 0.6 (30% EtOAc in petroleum ether (60-80)). 1 1-Bromo-1-(4-methylphenethyl)naphthalen-2(1H)-one (2f ). This reaction was carried out according to the general experimental procedure (A).…”

“…Dearomatization of planar arenes and development of its simple versions have been one of the core interests of our group. 1 Spirocyclic frameworks remain an immense area of attraction for chemists due to their challenging stereochemistry, wide scale application as chiral ligands and pharmaceutical interest 2 (Fig. 1).…”