Solid-phase synthesis on functionalised ¯uoropolymer resins. Part 1: Na®on resin sulfonamide-immobilised carboxylic acid derivatives and aryl vinyl sulfones Mahmoud Akhtar, Friedrich E. K. Kroll and David Gani* School of Chemistry, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK Received 1 March 2000; accepted 20 April 2000 Abstract The preparation and properties of Na®on resin sulfonamide systems derived from methyl glycinate and from 3-hydroxyethylaniline are described. Na®on derivatisation reactions were slow and maximum achievable functionalisations were 50% of the ion exchange capacity. In aqueous solution the resin derivatives were acid and base labile but in organic solvents the systems were stable to powerful nucleophiles and to heat. An aryl vinyl sulfone derivative used in the synthesis of tertiary amines aorded very pure products. # 2000 Elsevier Science Ltd. All rights reserved. Solid-phase organic synthesis (SPOS) is a useful and often complementary alternative to conventional solution-phase synthesis. SPOS normally involves `linking' molecules containing a reaction centre to a polymer support that is otherwise inert, and then elaborating the reaction centre. The reaction centre may be a substrate or a reagent. Advances in the range of chemistries that have been utilised on polymer supports are impressive 1 3 as are the underpinning advances in new resin materials, 4 resin functional groups, 4 linkers, 5 reagents, 6 resin cleavage protocols, 7,8 and analytical chemistry. 8,9 To date almost all eorts have been concerned with developing 1±2% cross-linked polystyrene-based systems for SPOS. Multiparallel SPOS is particularly useful in preparing libraries of related compounds and avoids many of the problems associated with assessing reaction eciency, purity and `deconvolution' in `split and mix' protocols. Recently we described POSAM TM , an ecient and versatile SPOS protocol for preparing compound libraries on the 0.01 to 1.0 mmol scale. 10 Here, the apparatus is constructed only from glass and PTFE and thus is suitable for reactions requiring particularly demanding conditions. Existing resin materials based upon polystyrene limit the utility of SPOS because polystyrene is mechanically fragile, unstable to oxidants, strong acids and bases and to temperatures above 120  C. Mindful of such limitations, we set-out to evaluate the potential of more stable polymers including those containing 0040-4039/00/$ - see front matter # 2000 Elsevier Science Ltd. All rights reserved. PII: S0040-4039(00)00646-8 Tetrahedron Letters 41 (2000) 4487±4491 * Corresponding author.