Herein we report the use of N-iodosuccinimide (NIS) as a bifunctional reagent for a regio-and (E)-selective C (sp 2 )-H sulfonylation reaction of styrenes. Styrenes and sulfonyl hydrazides treated with NIS and potassium carbonate in ethanol at 70°C resulted in (E)-vinyl sulfones exclusively with good to excellent yields. NIS, plays a dual role to generate sulfonyl radical from sulfonyl hydrazides at an initial stage and finally gives β-iodosulfone intermediate which was further converted to (E)-vinyl sulfones. Overall, a sustainable method for mild, metal free, convenient, one pot and direct synthesis of (E)-vinyl sulfones from styrenes are demonstrated via a CÀ S coupling reaction. Scheme 1. The present work: a) Direct synthesis of (E)-vinyl sulfone from styrenes using N-iodosuccinimide as b) The small molecule system chemistry approach via bifunctionality of NIS. . (E)-1-Methyl-4-((4-(trifluoromethyl)styryl)sulfonyl)benzene (3 ja): [22b] R f = 0.4 (20% ethyl acetate in hexane); white solid; yield 96% (128 mg); mp 120-124°C (lit. [22b] 120-122°C); 1 H NMR (400 MHz, CDCl 3 ) δ 7.83 (d, J = 8.2 Hz, 2H),7.67 (d, J = 15.4 Hz, 1H), 7.64 (d, J = 8.2 Hz, 2H), 7.58 (d, J = 8.2 Hz, 2H), 7.36 (d, J = 8.2 Hz, 2H), 6.94 (d, J = 15.4 Hz, 1H), 2.44 (s, 3H); 13 C NMR (175 MHz, CDCl 3 ) δ 145.0, 140.0, 137.3, 136.0, 132.7 (q, 2 (E)-4-(2-Tosylvinyl)benzonitrile (3 ka): [22b] R f = 0.4 (20% ethyl acetate in hexane); white solid; yield 91% (120 mg); mp 125-128°C (lit. [22b] 125-127°C); 1 H NMR (400 MHz, CDCl 3 ) δ 7.83 (d, J = 8.2 Hz, 2H), 7.68 (d, J = 8.4 Hz, 2H), 7.64 (d, J = 15.4 Hz, 1H), 7.56 (d, J = 8.4 Hz, 2H), 7.37 (d, J = 8.2 Hz, 2H), 6.95 (d, J = 15.4 Hz, 1H), 2.45 (s, (E)-1-Methyl-4-((4-nitrostyryl)sulfonyl)benzene (3 la): [28c] R f = 0.45 (20% ethyl acetate in hexane); white solid; yield 84% (103 mg); mp 172-174°C (lit. [28c] 172-175°C); 1 H NMR (700 MHz, CDCl 3 ) δ 8.24 (d, J = 8.8 Hz, 2H), 7.84 (d, J = 8.2 Hz, 2H), 7.69 (d, J = 15.4 Hz, 1H), 7.63 (d, J = 8.8 Hz, 2H), 7.38 (d, J = 8.2 Hz, 2H), 6.99 (d, J = 15.4 Hz, 1H), 2.45 (s, 3H); 13 (E)-1-Methyl-4-((4-nitrostyryl)sulfonyl)benzene (3 la): [28c] R f = 0.45 (20% ethyl acetate in hexane); white solid; yield 84% (103 mg); mp 172-174°C (lit. [28c] 172-175°C); 1 H NMR (700 MHz, CDCl 3 ) δ 8.24 (d, J = 8.8 Hz, 2H), 7.84 (d, J = 8.2 Hz, 2H), 7.69 (d, J = 15.4 Hz, 1H), 7.63 (d, J = 8.8 Hz, 2H), 7.38 (d, J = 8.2 Hz, 2H), 6.99 (d, J = 15.4 Hz, 1H), 2.45 (s, 3H); 13