PhI(OAc)2 induced intramolecular oxidative bromocyclization of homoallylic sulfonamides with KBr as the bromine source

Metal-free diamination of alkenes employing bromide catalysis

“…This is an unprecedented result as earlier combinations of bromide and PhI(OAc) 2 are essentially stoichiometric in halide. 23 Despite the exciting accomplishment of this first metal-free catalytic diamination, the present method retains the drawback of a stoichiometric amount of iodosobenzene diacetate. This renders the overall reaction rather cost intensive and requires the disposal of iodobenzene as a byproduct.…”

A one-pot oxidative decarboxylation–Friedel-Crafts reaction of acyclic α-amino acid derivatives activated by the combination of iodobenzene diacetate/iodine and iron dust

“…. 1 H NMR (400 MHz, CDCl 3 ) d 8.06 (d,J = 9.6 Hz,1H),2H),3H),6H),6.19 (s,2H), 3.80 (s, 9H); 13 C NMR d 166.27,160.8,158.8,142.8,135.1,131.3,128.6,128.1,127.0,126.5,126.4,110.2,91.5,56.1,55.4,47.4; IR (neat cm -1 ): v = 3445, 2938, 1661, 1510, 1332, 1204 cm -1 ; HRMS calcd for C 23 H 23 NNaO 4 ([M + Na] + ): 400.1525, found: 400.1524.…”

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

“…Various reagent systems (halogen/nitrogen sources) such as TsNH 2 –NBS ( Thakur et al, 2003 ; Chen et al, 2009a ; Chen et al, 2009b ; Shaikh et al, 2009 ; Wei et al, 2009a ; Wei et al, 2009b ; Cai et al, 2011 ; Yu et al, 2017 ), cyanamide–NBS ( Ponsold and Ihn, 1970 ), N-bromoacetamide ( Yeung et al, 2006a ; Yeung et al, 2006b ), N,N-dihalosulfonamides ( Kharasch and Priestley, 1939 ), S,S-dimethyl-N-(p-toluenesulfonyl)sulfilimine–NBS ( Raghavan et al, 2001 ), BocNH 2 /BocNBr 2 ( Chen et al, 2013 ), N,N-dihalocarbamates ( Śliwińska and Zwierzak, 2003 ) and N-halocarbamates ( Driguez et al, 1978 ) have been designed to carry out this transformation. To achieve high yields, excellent regioselectivities and diastereoselectivities, our group as well as others have developed efficient catalytic systems which comprise: metal and nonmetal powders ( Chen et al, 2009b ; Wei et al, 2009a ), metal oxides ( Thakur et al, 2003 ; Shaikh et al, 2009 ) and metal salts ( Albone et al, 1998 ; Ando et al, 1998 ; Li et al, 1999 ; Li et al, 2000 ; Wei et al, 2001 ; Yeung et al, 2006a ; Wang et al, 2008 ; Chen et al, 2009a ; Wei et al, 2009b ; Yadav et al, 2009 ), organic catalysts like hypervalent iodines ( Fan et al, 2007 ; Wang and Wu, 2007 ; Wu et al, 2008 ), phosphoric acid or phosphate ( Chen et al, 2010 ; Huang et al, 2011 ; Alix et al, 2012 ; Xie et al, 2013 ), noncatalytic routes which utilize Bronsted acids ( Wu and Wang, 2007 ) such as H 2 SO 4 or ionic liquid media [Bmim][BF 4 ]( Xu et al, 2004 ). Though considerable progress has been made in this area, drastic reaction conditions, procedural complexities, the use of metal catalysts and contamination of materials by metal traces ( Chen et al, 2003a ; Garrett and Prasad, 2004 ; Huang and Shaughnessy, 2006 ) limit their application.…”