Transition metal-catalyzed C H functionalization of arylacetic acids for the synthesis of benzothiadiazine 1,1-dioxides

Exciplex forming a Phenyl-Spaced Phenoxazine D–A Cohost for a Highly Efficient Red-Phosphorescent Organic Light-Emitting Diode

“…The first step involved a Buchwald-type C–N coupling of bromoaldehyde ( 2 ) with phenoxazine ( 1 ) and phenothiazine ( 4 ) . The intermediates ( 3 and 5 ) were then condensed with 1-(2-aminophenyl)­pyrrole ( 6 ) in the presence of Lewis-acid catalyst FeCl 3 to yield POZ–PQ and PTZ–PQ , respectively . In addition, PTZ-SA was synthesized by a condensing intermediate ( 5 ) with 2-aminobenzenesulfonamide in the presence of NaHSO 3 .…”

Effect of ortho-substitution on persulfate-mediated decarboxylation and functionalization of arylacetic acids

“…are required to induce decarboxylation and generate reactive intermediates required for subsequent coupling. 43 Of all the available literature protocols for decarboxylative coupling of arylacetic acids, [44][45][46][47][48] persulfate-mediated Homolytic cleavage of potassium persulfate generates a sulfate radical anion, which abstracts an electron from electron-rich species like carboxylic acids, especially ones attached to an aromatic ring system, thereby generating a radical cation that undergoes decarboxylation to generate the corresponding radical species. Although a couple of reports are available exemplifying persulfate-mediated decarboxylation, [49][50][51] the effect of ortho-substitution on the rate, or fate of decarboxylation is unexplored.…”

“…are required to induce decarboxylation and generate reactive intermediates required for subsequent coupling. 43 Of all the available literature protocols for decarboxylative coupling of arylacetic acids, 44–48 persulfate-mediated decarboxylation 49–51 (Scheme 1) and functionalization of arylacetic acids is the most explored.…”

Dithionite-Mediated Tandem Nitro Reduction/Imine Formation/Intramolecular Cyclization for the Synthesis of Dihydro-benzothiadiazine-1,1-dioxides

“…5 Conventionally, the 3,4-dihydrobenzothiadiazine-1,1-dioxides have been prepared by condensation of aldehydes with 2-aminobenzenesulfonamides under metal-catalyzed, metal-free catalytic or even noncatalytic reaction conditions. 6−10 Other approaches involve the use of aldehyde precursors such as benzyl alcohols, 11−14 arylacetic acids, 15 benzylamines, 16 and methylarenes. 17,18 The existing processes invariably use 2-aminobenzenesulfonamides as one of the starting materials, which obviously are prepared by the reduction of the corresponding 2-nitrobenzenesulfonamides.…”

“…Similarly, IDRA-21 is a modulator of the AMPK receptor and has been found to exert nootropic effects that improve cognitive abilities in animal studies (Figure ). Conventionally, the 3,4-dihydro-benzothiadiazine-1,1-dioxides have been prepared by condensation of aldehydes with 2-aminobenzenesulfonamides under metal-catalyzed, metal-free catalytic or even noncatalytic reaction conditions. − Other approaches involve the use of aldehyde precursors such as benzyl alcohols, − arylacetic acids, benzylamines, and methylarenes. , The existing processes invariably use 2-aminobenzenesulfonamides as one of the starting materials, which obviously are prepared by the reduction of the corresponding 2-nitrobenzenesulfonamides. As nitro compounds are feedstock chemicals, their reductive transformations to the synthesis of important nitrogen heterocycles could present an attractive synthetic strategy.…”