Terrahednm Lmers, zyxwvutsrqponmlkjihgfedcbaZYXW Vol. 35, No. 20, pp. 32253226, 1994 Elsevia Science Ltd Printed in Great Britain 0040-4039/‘94 $6.006).00 POTASSIUM TRIISOPROPYL8m OLATE: VINYL AND ARYL SULFIDES TI-IROUGH PD-CATALYZED CROSS COUPLING zyxwvutsrqponmlkjihgfedcbaZY Anil M. Rane.’ Edgar I. Miranda’ and John A. Soderquist* Department of Chemistry. University of Puerto Rico Rio Piedras. Puerto Rico 00931. Abstract: Vinyl and aryl halides are efliciedly converted, zyxwvutsrqponmlkjihgfedcbaZYXWVUTSR under Pd catalysis, with KSTIPS (I) to the corresponding silyl sulJies (2, 31. The naphthyl derivative was easily hydrolyzed to the mercaptan 4, or alkylated or alkenylated to provide unsymmetrical surides (6 61. A common feature of many natural products and pharmaceuticals. the sulRde functionality is also important in chemical synthesis.’ While numerous synthetic methods have been successfully employed to introduce this functionality into organic substrates. none appear more convenient than the known Pd-catalyzed coupling of vinyl halides with aryW.hiolates.’ However. the introduction of a silylthio. rather than ArS. group, would enable the silyl group to be subsequently replaced by a variety of alternative substituents. a feature which would markedly enhance the versatility of this approach to unsymmetrical sullides. Recently. we have discovered that triisopropylsilanethfol f HSTIPS ) can be readily prepared from TIPSCl and LiSH (98O/b) and converted to its stable. crystalline potassium salt, 1, (95%) with KH.6 The reagent is a powerful nucleophile which is readily alkylated by both lo and 2’ halides and tosylates to provide silyl alkyl sulRdes cleanly. The unusual resistance of these TIPS derivatives to both hydrolysis and cleavage by organometallic reagenls suggested that 1 might possess the necessary stabilily to undergo the coupling process previously observed only for the arylthiolates. Thus. nine representative alkenyl and aryl halides were selected. and all were found to be elI’iciently silanethiolated to produce the corresponding alkenyl (2) or aryl (3) silyl sulRdes under the Pd- catalyzed conditions.6 3 These results, which are presented in Table 1. reveal that the reaction proceeds with complete retention of configuration in the case of the vinyl derivatives examined (cJ entries 2 and 3) and give good to excellent product yields even on a small reaction scale. Eleclron-withdrawing groups enhance the rate of coupling of 1 with aryl bromides (cj entries 57.8). No reaction of 1 with p- BrC,H,NO, occurs in 6 h at 25 “C in the absense of the Pd catalyst. We chose to demonstrate the versatility of these silyl sullldes by elTecting the deprotection of 3225