Pergamon Tetrahedron 54 (1998) 4965-4976 TETRAHEDRON Aqueous Organotin Chemistry: Tin Hydride Mediated Dehalogenation of Organohalides and A Novel Organotin Mediated Nucleophilic Substitution on 2-Iodobenzoates in Water Koushik Das Sarma and Uday Maitra* Departmentof OrganicChemistry IndianInstitute of Science,Bangalore560 012, India [Fax: +91-80-344-3529; email:maitra@orgchem.iisc.emet.in] Received 3 November 1997; revised 2 March 1998; accepted 5 March 1998 Abstract: This paper describes the dehalogenation of water soluble and water insoluble organohalides in water by tri-n-butyltin hydride (TBTH), preformed TBTH and triphenyltin hydride (TPTH) in water. TBTH in the presence of a radical trap, and Ph4Snwere also found to effect nucleophilic substitution of 2-iodobenzoates in the presence of various nucleophiles. © 1998 ElsevierScienceLtd. All rights reserved. INTRODUCTION Tri-n-butyltin hydride (TBTH) and triphenyltin hydride (TPTH) are two of the most used organotin reagents in organic synthesis. They have found many applications in the generation of carbon radicals by atom abstraction (halides, selenides, sulfides), or by the addition to a multiple bond (alkene, alkyne and carbonyl compounds)) They are also used as a hydrogen donor for radicalsf a)' ~c) for hydrostannylation of alkenes, alkynes z and carbonyl compounds,3 in radical ring expansions, 4 radical oxygenations, 5 deoxygenations, 6 carbonylations 7and reduction ofcarbonyl compounds) The use of TBTH as a source of Bu3Sn and TPTH for hole-transfer-promoted hydrogenation are also known.9:° TBTH has been shown to act as a source of Nucleophilic hydride) ~ Polymer supported tin hydrides ~2 and internally coordinated tin reagents have also been described in the literature) 3 Though the applications of organotin reagents in organic synthesis are well explored, their solubility has limited them to organic solvents only. In recent years, the use of water as a solvent for organic synthesis has increased considerably.~4 However, because of the chemical incompatibility of many reducing agents with water, it is rarely used as a solvent in reductions, t5 We recently communicated a simple methodology to effect dehalogenation with TBTH in aqueous • Corresponding author. Alsoat The ChemicalBiology Unit,JawaharlalNehru Centrefor AdvancedScientific Research, Jakkur Campus,Bangalore560 064, India. 0040-4020/981519.00 © 1998 Elsevier Science Ltd. All rights reserved. PII: S0040-4020(98)00202-6