Use of Bromine and Bromo-Organic Compounds in Organic Synthesis Indranirekha Saikia, Arun Jyoti Borah, and Prodeep Phukan* Department of Chemistry, Gauahti University, Guwahati-781014, Assam, India ABSTRACT: Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring- opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis. CONTENTS 1. Introduction B 2. Scope of This Review B 3. Bromination Reactions C 3.1. Bromination with Molecular Bromine C 3.1.1. Bromination of Olefinic Compounds Using Molecular Bromine C 3.1.2. Bromination of the Aliphatic C−H Bond Using Molecular Bromine H 3.1.3. Aromatic Ring Bromination Using Mo- lecular Bromine N 3.1.4. Bromination of Heterocyclic Com- pounds with Molecular Bromine X 3.1.5. Bromination of Naturally Occurring Compounds Using Molecular Bromine AD 3.1.6. Miscellaneous Bromination Reactions Using Molecular Bromine AF 3.2. Bromination with Bromo-Organic Com- pounds AH 3.2.1. Bromination with NBS AH 3.2.2. Bromination with Other Bromo-Organic Compounds BA 3.3. Reagents Other Than Bromo-Organic as Well as Naturally Occurring Bromo Com- pounds CC 3.3.1. HOBr CC 3.3.2. Phosphorus Oxybromide CC 3.3.3. Triphasic System of Bu 4 N + HSO 4 − , NaBr, and NaOCl CD 3.3.4. Ammonium Bromide CD 3.3.5. Iodine Monobromide CD 3.3.6. Boron Tribromide CE 3.3.7. Bromine Chloride CE 3.3.8. Thionyl Bromide CE 3.3.9. Bromine Fluoride CF 3.3.10. Bromine Triflouride CG 3.3.11. HBr CG 3.3.12. Bromoiodinanes CH 3.3.13. Alkyl Hypobromites CH 3.3.14. Natural Sources CH 4. Cohalogenation Reactions CI 4.1. Cohalogenation Reactions Using Molecular Bromine CI 4.2. Cohalogenation Reaction with NBS CI 4.3. Cohalogenation Reaction with Other Bromo-Organic Compounds CP 5. Oxidation Reactions CS 5.1. Use of Molecular Bromine as an Oxidant CS 5.2. Application of NBS to Oxidation Reactions CU 5.3. Oxidation Reactions Using Other Bromo- Organic Compounds DC 6. Cyclization Reactions DF 6.1. Use of Molecular Bromine for Cyclization Reactions DF 6.2. Use of NBS in Cyclization Reactions DH 6.3. Cyclization Reactions Using Other Bromo Compounds DN 7. Formation of Nitro Compounds DO 7.1. Formation of Nitro Compounds Using Bromonitromethane DO 7.2. Use of Other Bromo-Organic Compounds for the Formation of Nitro Compounds DP 8. Rearrangement Reactions DQ 8.1. Molecular Bromine-Assisted Rearrangement Reactions DQ 8.2. Rearrangement Reactions Using NBS DQ Received: September 1, 2015 Review pubs.acs.org/CR © XXXX American Chemical Society A DOI: 10.1021/acs.chemrev.5b00400 Chem. Rev. XXXX, XXX, XXX−XXX