Hypervalent Iodine (III) Catalyzed Regio- and Diastereoselective Aminochlorination of Tailored Electron Deficient Olefins via GAP Chemistry

Abstract

Herein, we report a protocol for highly efficient hypervalent iodine (III) mediated, group-assisted purification (GAP) method for the regioselectivities and stereoselective aminochlorination of electron-deficient olefins. A series of vicinal chloramines with multifunctionalities were acquired in moderate to excellent yields (45-94%), by merely mixing the GAP auxiliary-anchored substrates with dichloramine T and tosylamide as chlorine/nitrogen sources and iodobenzene diacetate as a catalyst. The vicinal chloramines were obtained without any column chromatographic purification and recrystallization simply by washing the reaction mixture with a minimum amount of common inexpensive solvents and thus avoiding wastage of silica, solvents, time, and labor. The GAP auxiliary is recyclable and reusable. This strategy is easy to handle, cost-effective, greener, sustainable, environmentally benign, and mostly suitable for the syntheses of vicinal haloamines from various electron-deficient alkenes.

Regio- and Diastereoselective Vicinal Aminobromination of Electron Deficient Olefins via Phosphorus-Based GAP Protocol

“…Based on our prior research, we were interested in aminobromination of α,β-unsaturated cinnamic acids, which are challenging due to the formation of regio-and diastereomeric products. To develop conditions for regio-and diastereoselective transformation, we began to prepare the GAP coupled intermediate 1a-k and 2a-k in our laboratory according to the literature procedure (Rahman et al, 2020) given in supporting information. To optimize the reaction conditions, we initiated the study with the GAP anchored intermediate 1a as the test substrate, p-toluenesulfonamide (4-TsNH 2 ) and N-bromosuccinimide (NBS) as the nitrogen and bromine source respectively.…”

Progress in organocatalysis with hypervalent iodine catalysts

“…In 2022, a methodology of group-assisted purification (GAP) was adopted by Ali and co-workers for the regioselective and stereoselective synthesis of vicinal chloroamines 39 from electron-deficient cinnamates and cinnamamides 36 tethered with benzyldiphenylphosphine oxide (Bndpp) group as the GAP candidate (Scheme 8). 75 The reaction was carried out by refluxing GAP anchored substrates 36 in the presence of 4 Å molecular sieves, PhI(OAc) 2 1 as catalyst, 4-TsNH 2 37 and 4-TsNCl 2 38 as the nitrogen and chlorine source, respectively, in dichloromethane under argon atmosphere. This protocol tolerated an array of functional groups providing products 39 in good yields.…”

New multiple-layered 3D polymers showing aggregation-induced emission and polarization

“… 13 As opposed to traditional planar or helical skeletons, this chirality displays rotational stereoisomerism. It was the Group-Assisted Purification (GAP) chemistry 14 that led to our first multilayer 3D chirality 13 a in which dual Buchwald–Hartwig cross-coupling 15 played an important role.…”