Activator free, expeditious and eco-friendly chlorination of activated arenes by N-chloro-N-(phenylsulfonyl)benzene sulfonamide (NCBSI)

NCBSI/KI: A Reagent System for Iodination of Aromatics through In Situ Generation of I-Cl

“…29 Similarly, in situ I-Cl generation followed by iodination were reported using NCS/ NaI-trifluoroacetic anhydride 30 and NCS/KI−HI system. 31 The NCS activation correlates the need for protonation of the carbonyl group to increase the bond length from 1.707 to1.825 Å and generate the electrophile reported by Prakash et al 21 After working on chlorination of aromatics and oxidation of alcohols using NCBSI reagent, 32,33 our research group has developed an iodinating system of NCBSI/KI, which generates I-Cl in situ without activation. We were keen on applying this protocol for the iodination of activated arenes.…”

“…After working on chlorination of aromatics and oxidation of alcohols using NCBSI reagent, , our research group has developed an iodinating system of NCBSI/KI, which generates I-Cl in situ without activation. We were keen on applying this protocol for the iodination of activated arenes.…”

“…We were keen on applying this protocol for the iodination of activated arenes. Our previous research on NCBSI reagent revealed high electrophilicity due to a longer bond length (1.848 Å), lower BDE (40.36 kcal mol –1 ), and higher absolute charge density on nitrogen (−0.658) compared to other N -chloro reagents. , Therefore, we investigated the formation of I-Cl by reaction of various N -chloro reagents with potassium iodide in anhydrous acetonitrile over 12 h (Table ).…”

Continuous-Flow Hofmann Rearrangement Using Trichloroisocyanuric Acid for the Preparation of 2-Benzoxazolinone

“…The white solid cyanuric acid could either be safely disposed as it slowly degrades (biodegradable) or recovered for reuse. TCCA has widely been described as an efficient chlorinating agent for ketones, alkenes, acids, esters, arenes, heterocycles, imides, and amides for the synthesis of α-chloro ketones, esters, chlorohydrins, N- chloroamides, N- chloroimides, and chloro-substituted arenes or heterocycles. ,,− It has also found value in converting carboxylic acids into acid chlorides when coupled with strong Lewis bases such as triphenylphosphine to avoid the use of noxious reagents such POCl 3 , PCl 5 , and SOCl 2 . − Recently, it has been employed as an alternative and more selective agent for the halogenation of methane to chloromethane. − …”

Chlorination of arenes via the degradation of toxic chlorophenols

“…Chlorination of arenes is usually carried out with toxic and corrosive reagents ( 32 – 34 ). Less toxic and more selective chlorination reagents tend to be expensive [e.g., chloroamides ( 35 , 36 )] and are not atom economic ( 37 – 39 ). Consequently, from the perspective of sustainability, the ability to transfer a chloro group from unwanted chlorophenols to other substrates would be advantageous.…”