Alkenes palladium-catalyzed arylation

The palladium-catalyzed arylation of alkenes by haloarenes, and applications in furan synthesis have been described earlier (see Eq. 14 in Section IV,B, 1). By employing o-aminoiodoarenes and appropriately substituted (Z)-alkenes it has proved possible to develop an efficient synthetic route to quinolin-2-ones (Scheme 140).213... 

Van Srijdonck GPF, Boete MDK, van Leeuwen PWN (1999) Fast palladium catalyzed arylation of alkenes using bulky monodentate phosphorus ligands. Eur J Inorg Chem 1073-1076... 

A number of methods are now available for the palladium-catalyzed arylation of alkenes. Mizoroki et al. showed that, in the presence of PdCl2, iodobenzene reacted with ethylene to give styrene.623 These reactions require a stoichiometric amount of base to neutralize the hydriodic acid formed (equation 172). 

Analogous to the palladium-catalyzed arylation of alkenes with aryl halides (Section 61.2.8.4), vinyl halides can be used to prepare dienes according to equation (191).649 A base is again needed in stoichiometric quantities. It should be noted that the dienes can be isolated as such only in certain cases. When vinyl iodide itself was used, only Diels-Alder products were obtained (Scheme 74). 

He, H.S., Zhang, C., Ng, C.K.-W. and Toy, P.H. (2005a) Polystyrene-supported triphenylarsines useful ligands in palladium-catalyzed aryl halide homocoupling reactions and a catalyst for alkene epoxidation using hydrogen peroxide. Tetrahedron, 61(51), 12053-57. 

Although a reasonable working hypothesis has been established for the mechanism of the palladium-catalyzed arylation and alkenylation of alkenes (the Heck reaction), individual... 

Palladium-catalyzed arylation and vinylation of alkene is referred to as the Mizoroki-Heck reaction and is one of the most widely used Pd(0)-catalyzed C-C bond formations in organic synthesis. However, the reaction has not been extensively employed for C-glycosylation [96]. The example shown in O Scheme 67 outlines the reaction of iodopyridine and furanose gly-cal for the synthesis of C-nucleoside [97]. The mechanism began with the oxidative addition of iodopyridine to Pd(0) catalyst, and the resulting organo-palladium species was inserted by... 

Shibasaki, M., VogI, E. M. The palladium-catalyzed arylation and vinylation of alkenes-enantioselective fashion. J. Organomet. Chem. 1999,576, 1-15. 

The palladium-catalyzed arylation of alkenes and arenes offers one of the conceptually most intelligent solutions for the synthesis of PAHs from the appropriate aryl halides or triflates. The reaction is usually carried out in a polar solvent (AT,AT-dimethylformamide (DMF) or AT,AT-dimethylacetamide (DMA)) at relatively high temperatures (100-170°C) with a base to trap the acid formed, and a phase transfer catalyst. Most often Pd(II) acetate or a Pd(II) complex are used, that are converted to a catalytically active Pd(0) species in the course of the reaction. The mechanisms of these Heck reactions have been discussed widely throughout the pertinent literature [78,79]. 

The mtermolecular palladium-catalyzed arylation of alkenes (classical Heck reaction) has been used e.g. to synthesize the highly strained hexaarylethane derivative 72 in a very straight-forward fashion (see Scheme 37 [130]). The X-ray structure investigations of 72 and similar propellanes revealed an elongation of the central CC single bond to ca. 162 pm [130c]. 

Blaser, H.-U. and Spencer, A. (1982) The palladium-catalyzed arylation of activated alkenes with aroyl chlorides. J. Organomet. Chem., 233, 267-7A. 

Scheme 1.15 Palladium-catalyzed arylation of alkene 42 (Mizoroki, 1971).

Palladium-Catalyzed Arylation Reactions of Alkenes (Mizoroki-Heck Reaction and Related Processes)... 

Heck reaction, palladium-catalyzed cross-coupling reactions between organohalides or triflates with olefins (72JOC2320), can take place inter- or intra-molecularly. It is a powerful carbon-carbon bond forming reaction for the preparation of alkenyl- and aryl-substituted alkenes in which only a catalytic amount of a palladium(O) complex is required. 

Palladium-catalyzed reaction of alkyne 47 with a variety of aryl and vinyl halides afforded alkenes 48 in good yield. Cyclization to quinolines 49 was performed by treating 4 8 with TsOH in EtOH <96T(52)10225>. 

Some years ago we began a program to explore the scope of the palladium-catalyzed annulation of alkenes, dienes and alkynes by functionally-substituted aryl and vinylic halides or triflates as a convenient approach to a wide variety of heterocycles and carbocycles. We subsequently reported annulations involving 1,2-, 1,3- and 1,4-dienes unsaturated cyclopropanes and cyclobutanes cyclic and bicyclic alkenes and alkynes, much of which was reviewed in 1999 (Scheme l).1 In recent days our work has concentrated on the annulation of alkynes. Recent developments in this area will be reviewed and some novel palladium migration processes that have been discovered during the course of this work will be discussed. 

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