Ley reagent

Pr N)[RuO ] (TPAP) and ("Bu N)[RuO ] (TBAP) The acronyms TRAP and TBAP were coined in 1987 [452], The most frequently used is TPAP (CAS number 114615-82-6) very occasionally it is called the Griffith, Ley or Griffith-Ley reagent, but here TPAP is used throughout. 

LEY - GRIFFITH Oxidation reagent Oxidation ol alcotwls to caitxnyl compounds with a pemjthenate catalyst and N-methylmorpholine - N-oxIde (NMO), In the presence of other functional gmups... 

S. V. Ley, l.R. Baxendale, G. Brusotti, M. Caldarelli, A. Massi and M. Nesi, Solid-supported Reagents for Multi-step Organic Synthesis Preparation and Application, II Farmaco 57 321-330 2002. 

Baxendale, I.R., Brusotti, G., Matsuoka, M., Ley, S.V. (2002) Synthesis of Nornicotine, Nicotine, and Other Functionalised Derivatives Using Solid-supported Reagents and Scavengers. Journal of the Chemical Society Perkin Transactions 1, 143-154. 

Ley, S.V., Schucht, O., Thomas, A.W., Murray, P.J. (1999) Synthesis of the Alkaloids ( )-Oxomaritidine and ( )-Epimaritidine Using an Orchestrated Multi-Step Sequence of Polymer Supported Reagents. Journal of the Chemical Society Perkin Transactions I, 1251-1252. 

Ley and Baxendale have shown that it is possible to complete a total synthesis by using a number of flow devices in series, which contained immobihzed reagents (14). Use of a number of CCSs in series would allow cascade catalysis in which the catalytic systems have been separated (Figure 4.2). This is quite attractive in view of the fact that often each catalyst needs highly specific operating conditions, such as temperature and pH. 

The microwave-assisted thionation of amides has been studied by Ley and coworkers using a polymer-supported thionating reagent [115]. This polymer-supported amino thiophosphate serves as a convenient substitute for its homogeneous analogue in the microwave-induced rapid conversion of amides to thioamides. Under microwave conditions, the reaction is complete within 15 min, as opposed to 30 h by conventional reflux in toluene (Scheme 7.95). The reaction has been studied for a range of secondary and tertiary amides and GC-MS monitoring showed that it proceeded almost quantitatively. More importantly, this work was the first incidence of the use of the ionic liquid l-ethyl-3-methylimidazolium hexafluorophosphate... 

The conversion of isothiocyanates to isonitriles under microwave conditions has been studied by Ley and Taylor using a polymer-supported [l,3,2]oxaphospholidine [119]. The use of 3-methyl-2-phenyl-[l,3,2]oxaphospholidine in solution is less favored [120] due to the associated toxicity and instability of the phosphorus-derived reagent, as well as the need to isolate the products from a complex reaction mixture by vacuum distillation. This drawback has been resolved by attaching the active [l,3,2]oxaphospholidine to a polymer matrix. 

Baxendale IR, Ley SV (2000) Polymer-supported reagents for multi-step organic synthesis application to the synthesis of sildenafil. Bioorg Med Chem Lett 10 1983-1986... 

Baxendale IR, Lee A-L, Ley SV (2001) A concise synthesis of the natural product carpanone using solid-supported reagents and scavengers. Synlett 482-484... 

Baxendale IR, Ley SV, Ernst M, Krahnert W-R (2002e) Application of polymer-supported enzymes and reagents in the synthesis of y-aminobutyric acid (GABA) analogues. Synlett 1641-1644... 

Baxendale IR, Ley SV, Smith CD, Tranmer GK (2006d) A flow reactor process for the synthesis of peptides utilizing immobilized reagents, scavengers and catch and release protocols. J Chem Soc Chem Commun 4835-4837... 

Jamieson C, Congreave MS, Emiabata-Smith DF, Ley SV (2000) A rapid approach for the optimisation of polymer supported reagents in synthesis. Synlett 603-607... 

Ley SV, Baxendale IR (2002b) New tools and concepts for modern organic synthesis. Nat Rev Drug Disc 1 573-586 Ley S V, Massi A (2000) J Comb Chem Polymer supported reagents in synthesis preparation of bicyclo[2.2.2]octane derivatives via tandem michael addition reactions and subsequent combinatorial decoration. 2 104—107 Ley SV, Schucht O, Thomas AW, Murray PJ (1999) Synthesis of the alkaloids ( )-oxomaritidine and ( )-epimaritidine using an orchestrated multi-step sequence of polymer supported reagents. J Chem Soc Perkin Trans 1 1251— 1252... 

Ley S V, Baxendale IR, Brusotti G, Caldarelli M, Massi A (2002b) Solid-supported reagents for multi-step organic synthesis preparation and application. Farmaco 57 321-330... 

Ley S V, Baxendale IR, Myers RM (2006) The use of polymer supported reagents and scavengers in the synthesis of natural products. In Boldi AM (ed) Combinatorial synthesis of natural product-based libraries. CRC Press Boca-Raton, pp 131-163... 

Storer RI, Takemoto T, Jackson PS, Ley SV (2003) A total synthesis of epo-thilones using solid-supported reagents and scavengers. Angew Chem Int Ed 42 2521-2525... 

M. Calderelli, J. Habermann, S. V. Ley, Clean Five-Step Synthesis of an Array of 1,2,3,4-Tetra-substituted Pyrroles using Polymer-Supported Reagents , J. Chem. Soc, Perkin Trans. 11999,107-110. 

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