F-dppp

Studies on the controlled microwave-irradiated novel palladium-catalyzed reaction of a fluorous-tagged bidentate ligand (l,3-bis(diphenylphosphino) propane ligand, [F-dppp]) for regioselective Heck vinylations of enamides have... 

Abbreviations acac, acetylacetonate Aik, alkyl AN, acetonitrile bpy, 2,2 -bipyridine Bu, butyl cod, 1,5- or 1,4-cyclooctadiene coe, cyclooctene cot, cyclooctatetraene Cp, cyclopentadienyl Cp, pentamethylcyclopenladienyl Cy, cyclohexyl dme, 1,2-dimethoxyethane dpe, bis(diphenyl-phosphino)ethane dppen, cis-l,2-bis(di[Atenylphosphino)ethylene dppm, bis(diphenylphosphino) methane dppp, l,3-bis(diphenylphosphino)propane eda,ethylenediamine Et,ethyl Hal,halide Hpz, pyrazole HPz, variously substituted pyrazoles Hpz, 3,5-dimethylpyrazole Me, methyl Mes, mesityl nbd, notboma-2,5-diene OBor, (lS)-endo-(-)-bomoxy Ph, phenyl phen, LlO-phenanthroline Pr, f opyl py, pyridine pz, pyrazolate Pz, variously substituted pyrazolates pz, 3,5-dimethylpyrazolate solv, solvent tfb, tetrafluorobenzo(5,6]bicyclo(2.2.2]octa-2,5,7-triene (tetrafluorobenzobanelene) THE, tetrahydrofuran tht, tetrahydrothicphene Tol, tolyl. 

Scheme 15. Retrosynthetic Analysis and Synthesis of Methyl Trisporate B a C4H9Li then 43 then KH/THF followed by TMS-C1, C5H5N, ether 70% b FVT, 95% CH3OH, HC(OCH,)3, HC1, 68% d CH3MgBr, (dppp)NiCl2, THF, 75% HC1, H20, CH3CN, 100% f See Ref. 975...

In CH2CI2, where the reaction of the bis-chelate complex (1) with Pd(OAc)2 to give (2) is much faster than in MeOH (Figure 7.5), no significant difference between dppe or dppp Pd" catalysts has been observed in CO/ethene copolymerisation [5e,f]. 

Bianchini has reported that the migratory insertion reactions of [Pd(R)(CO)(P-P)]+ complexes (R = Me, Et) are reversible and follow first-order kinetics irrespective of the chelating diphosphine (P-P = dppp, dppe, meso-dppb, rac-dppb, meso-bdpp, rac-bdpp) [5e, f]. The free energies of activation for these reactions were calculated from the half-life times (tj 2) obtained by P( H HP NMR spectroscopy as all the rates of conversion of the methyl carbonyl complexes were independent of the CO pressure. Therefore, the AG values associated with the migratory insertion of the methyl carbonyl complexes could be straightforwardly calculated from the values using the equation AG = RT(ln k -ln kT/h) with = In First-order... 

Coordination via the f/rreo-contigured diol at 02 and 03 is also favored by (dppp)Pt. Species using the central erythro-diol or one of the terminal non-stereogenic diols have been detected in small amounts only [22]. 

---