Phosphines Organic Syntheses procedures

Acid amide-triphenylphosphine dihalide adducts (4) have found wide application in organic synthesis. - Synthetic equivalents are adducts (5) from acid amides and triphenylphosphine/CCU, which are prepared in situ from the educts. - With these reagents the following transformations have been performed dehydration of amides or aldoximes to nitriles, preparation of isonitriles from secondary form-amides, preparation of imidoyl halides from amides or acylhydrazines and preparation of ketene imines from amides. Using polymer-supported triphenylphosphine the work-up procedure is much easier to achieve. Triphenylphosphine can be replaced by tris(dialkylamino)phosphines. - Instead of CCI4 hexa-chloroethane, hexabromoethane or l,l,2,2-tetrabromo-l,2-dichloroethane can be used " the adducts thus formed are assumed to be more effective than those from the triphenylphosphine/CCU system. 

Interestingly, the procedure of hydroxycarbonylation by using lithium formate and acetic anhydride as internal condensed sources of carbon monoxide can be carried out in the presence of a recoverable and reusable phosphine-free palladium-carbon aerogel catalyst [61]. To support high-speed chemistry and automated organic synthesis, an operationally simple and environmentally safe hydroxycarbonylation of vinyl triflates can... 

This is an efficient procedure for the synthesis of 2-allq l/aiyl substituted henzo[Z>]furans/nitrohenzo[Z>]furans with water as the solvent. In the presence of PPhs, Cul and prolinol, the corresponding products were formed in good yields (Scheme 2.59). The protocol does not require the use of a phase transfer catalyst or water-soluhle phosphine ligands and is free from the use of any organic co-solvent. As the authors demonstrated, this is the first Pd/C mediated synthesis of henzofuran derivatives, hut the lack of recycling ability was shown in the manuscript. Temperature proved to be critical no product could be observed at room temperature. 

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