Thiophenol, polymer-supported

Thiophenol-mediated Alkene Inversion. /rans-Substituted 

Heterocyclic Synthesis. The reaction of 1,2,3-benzothiadia-zole with PhSH/AIBN in refluxing EtOAc provides a mixture of products including dibenzo[c,e]-o-dithiin (1), thianthrene (2), and 2-(phenylthio)diphenyl disulfide (3).  

Physical Data loading 1.0-1.5 mmol g (based on benzyl bromide uptake). 

Solubility 1% cross-linked polystyrene backbone is insoluble in all common aqueous and organic solvents. 

Form Supplied in yellow powder bead size 75-150 pun, 100-200 mesh (95% within). Commercially available retailer Argonaut Technologies.  

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The use of numerous polymer-supported optically active phase transfer catalysts was further extended by Kelly and Sherrington11351 in a range of phase transfer reactions including a variety of displacement reactions, such as sodium borohydride reductions of prochiral ketones, epoxidation of chalcone, addition of nitromethane to chalcone and the addition of thiophenol to cyclohexanone. Except in the chalcone epoxidation, all the examined resin catalysts proved to be very effective. However, with none of the chiral catalyst system examined was any significant ee achieved. The absence of chiral induction is a matter of debate, in particular over the possible reversibility of a step and the minimal interaction within an ion pair capable of acting as chiral entities in the transition state and/or the possible degradation of catalysts and leaching. 

The heterobimetallic catalyst prepared from (R,R)-3-aza-benzyl-l,5-dihydroxy-l,5-diphenylpentane was used for the asymmetric Michael addition reaction of malo-nates and thiophenols to enones [49]. The polymer-supported version of the chiral... 

Scheme 19.36 Asymmetric Michael addition of thiophenols to cyclic enones catalysed by a polymer-supported aluminium complex.

In a related and more recent study a variety of solid-supported acylating agents were synthesized and used for microwave-mediated transformation of amines, alcohols, phenols, and thiophenols [123]. In a microwave-mediated procedure, Mer-rifield resin was first modified by attaching 1,4-butanediol to introduce a spacer unit. Bromination and subsequent reaction with commercially available 6-methyl-2-thiouracil then treatment with corresponding acyl chloride afforded the desired polymer-bound pyrimidines (Scheme 16.81). The acylating ability of this supported reagent has been proven by reaction with benzylamine. 

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