J. Iran. Chem. Soc., Vol. 4, No. 2, June 2007, pp. 126-174. JOURNAL OF THE Iranian Chemical Society Application of N-Halo Reagents in Organic Synthesis E. Kolvari a , A. Ghorbani-Choghamarani b , P. Salehi c , F. Shirini d and M.A. Zolfigol a, * a Faculty of Chemistry, Bu-Ali Sina University, Hamedan, 6517838683, Iran b Department of Chemistry, Faculty of Science, Ilam University, Ilam, Iran c Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Evin, Tehran, Iran d Department of Chemistry, Faculty of Science, Guilan University, Rasht, Iran (Received 11 April 2007, Accepted 1 May 2007) This review article summarizes published data on the application of N-halo reagents (such as N-halo amines, N-halo amides and/or imides, N-halo sulfonamides and/or imides, and etc.) in various organic functional group transformations such as: oxidation reactions, deprotection and protection of different functional groups, halogenation of saturated and unsaturated compounds, acylation of alcohols, phenols, amines or thiols, epoxidation of alkenes, aziridination and etc. The main purpose of writing this review is encouraging of active researchers interested to this field for the synthesis of new N-halo reagents specially with different halogens and applications of these new N-halo reagents in organic reactions or finding more and more applications of existing N-halo reagents in organic synthesis. Keywords: N-Halo reagents, N-Halo imides, N-Halo amines, N-Halo sulfonamides, N-Halo amides, N-Halo sulfonimides This article is dedicated to Professor Seyyed Ahmad Banihashemi one of the founders of polymer chemistry in Iran on the occasion of his 75th birthday. INTRODUCTION Synthetic methodology, as the building block of organic synthesis, continuously seeks for new reagents, better reaction conditions, and more efficient and selective methods. In this regard, a large group of compounds entitled N-halo reagents are widely used in fine organic synthesis. These include N- halo derivatives of amines, amides, imides, urea, saccharines, sulfonamides, sulfonimides, and etc. Although the scope of the *Corresponding author. E-mail: zolfi@basu.ac.ir application of such compounds is so wide that all N-halo reagents can not be considered within the framework of a single review article, but we decide to introduce them briefly and believe that it may be useful to achieve new idea and applications. In the other way, the chemistry of N-halo reagents was the subject of several review articles [1-8]. However, since that time numerous new data has been appeared in the literature which are summarized in the present review. Some specific features of N-halo reagents such as high activity of the N-X bond and various modes of its splitting, determine their wide application in organic synthesis.