Aryl alkenes synthesis

Arenesulphinylation 264 Arenesulphinylethanes, synthesis of 267 2-Arenesulphonyl-3-aryloxaziridines, as oxidizing agents 254 Arenesulphonyl azides, reactions of 641 At-Arenesulphonyliminopyridinium betaines, mass spectra of 160-162 Arenesulphonyl radicals 215, 1091 Aryldiazonium salts, reactions of 280, 281 Aryl(methylsulphinyl)(methylthio)alkenes, synthesis of 614... 

The same authors recently described the synthesis of similar rhodium-complexed dendrimers supported on a resin having both interior and exterior functional groups. These were tested as catalysts for the hydroformylation of aryl alkenes and vinyl esters (52). The results show that the reactions proceeded with high selectivity for the branched aldehydes, with excellent yields, even up to the tenth cycle. The hydroformylation experiments were carried out with first- and a second-generation rhodium-complexed dendrimers as catalysts, with a mixture of 34.5 bar of CO and 34.5 bar of H2 in dichloromethane at room temperature. Each catalyst was easily recovered by simple filtration and was reusable for at least six more cycles without... 

The method employing the sequential alkylation and elimination of sulfoxides, reported above, has been successfully applied to the synthesis of dienes (Scheme 86, entry c), aryl alkenes and dienes (Scheme 47), vinyl sulfides, a,3-unsaturated sulfoxides, vinyl fluorides and vinyl chlorides (Scheme 96, entry a), and 1,1-dichloro-l-alkenes (Scheme 96, entry b). ... 

Topics of relevance to the content of this chapter which have been reviewed during the year include photoactive [2]rotaxanes and [2]catenanes, photochemical synthesis of macrocycles, phototransformations of phthalimido amino acids, photoaddition reactions of amines with aryl alkenes and arenes, photoreactions between arenenitriles and benzylic donors, photostability of drugs, polycyclic heterocycles from aryl- and heteroaryl-2-propenoic acids, photoreactions of pyrroles, photoamination reactions in heterocyclic synthesis, switching of chirality by light, photochromic diarylethenes for molecular photoionics and solid state bimolecular photoreactions. 

Over the past two decades, Pd- or Ni-catalyzed cross-coupling, especially Pd-catalyzed version, has become one of the most common methods (possibly the most common method) for highly selective synthesis of arylated alkenes, conjugated dienes, conjugated enynes (Sect, in.2.8), and other related aUcene derivatives, hi addition to Mg, Zn, Al, and Zr used since the 1970s, several other metals including Sn,[2 ] [27] and Cu[2 ] [ i have been extensively employed since around 1980. 

TABLE 1. Some Preferred Alkenyl Reagents for the Synthesis of Arylated Alkenes via Pd- or Ni-Catalyzed Cross-Conpling and Preferred Cross-Conpling Protocols... 

An alternative approach to the synthesis of stereodefined arylated alkenes by the Pd-catalyzed cross-coupling involves the reaction of arylmetals with alkenyl electrophiles, i.e., aryl-alkenyl coupling (Sect. A). Table 8 summarizes some representative examples of the Pd-catalyzed aryl-alkenyl coupling reactions. 

Bauer, A. Miller, M. W. Vice, S. F. McCombie, S. W. 2001. Suzuki arylation of 1,1-dibromo-l-alkenes Synthesis of tetra-substituted alkenes. Synlett 254—256. 

Evans, W. J., Ulibarri, T. A., Ziller, J. W. Reactivity of (C5Mes)2Sm with aryl-substituted alkenes Synthesis and structure of a bimetallic styrene complex that contains an tj -arene lanthanide interaction./. A/w. Chem. 5 oc., 112,219-223 (1990). 

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