Aryl and Alkynyl Derivatives

As in the reactions of N3P3F6 with methyl-lithium, replacement of the first two fluorine atoms in the same substrate by phenylethynyl-lithium occurs by a predominantly geminal reaction path  

The monophenylethynyl derivative reacts readily with dicobalt octacarbonyl to give the complex formulated as (40). 

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Tsutsui and Ely have extended the general method for preparing a-bonded actinide complexes to the synthesis of compounds containing lanthanide-carbon a-bonds (37,38,39). Using the reaction shown in eq.3, they synthesized a number of alkyl, aryl, and alkynyl derivatives. The metals chosen vary from Gd to Yb. Like their uranium analogs, they are oxygen and moisture sensitive, but they are surprisingly thermally stable. 

I copper can be prepared by reduction )th lithium naphthalcnidc under argon, dides at 0-25° to form organocopper rmed undergoes self-coupling almost X derived from aryl and alkynyl halides arc reduced to ArH. These arylcopper d chlorides and allylic and benzylic... 

This chapter covers recent information on the preparation, physical properties, and reactions of quinoxaline and its C-alkyl, C-aryl, iV-alkyl, and A-aryl derivatives as well as their respective ring-reduced analogs. In addition, it includes methods for introducing alkyl or aryl groups (substituted or otherwise) into quinoxalines already bearing substituents and the reactions specific to the alkyl or aryl groups in such compounds. For simplicity, the term alkylquinoxaline in this chapter is intended to include alkyl-, alkenyl-, alkynyl-, and aralkylquinoxalines likewise, arylquino-xaline includes both aryl- and heteroarylquinoxalines. 

An earlier review treated the organometallic derivatives, including alkyl, aryl, vinyl, alkynyl, carbonyl, carbene, alkene and alkyne complexes,16 and these will not be treated here (see Table 1 for other books and reviews on organogold chemistry). Two important articles dealing with [AuCl(CO)], including its structure and catalytic properties, have been published recently.97,381... 

Addition of organometallic reagents to imines is not limited to allylmetal derivatives. Hoveyda and Snapper have demonstrated that dialkylzinc reagents can add to imines in a one-pot procedure. Using a zirconium complex as metal catalyst and a chiral peptide, diverse enantioenriched aryl, aliphatic and alkynyl amines 142 have been obtained with high levels of enantioselectivity (Scheme 8.60) [136],... 

Recent progress on the use of hypervalent iodine reagents for the construction of carbon-het-eroatom (N, O, P, S, Se, Te, X) bonds is reviewed. Reactions of aryl-A3-iodanes with organic substrates are considered first and are loosely organized by functional group, separate sections being devoted to carbon-azide and carbon-fluorine bond formation. Arylations and alkenyla-tions of nucleophilic species with diaryliodonium and alkenyl(aryl)iodonium salts, and a variety of transformations of alkynyl(aryl)iodonium salts with heteroatom nucleophiles are then detailed. Finally, the use of sulfonyliminoiodanes as aziridination and amidation reagents, and reactions of iodonium enolates formally derived from monoketones are summarized. 

Various aryl, alkenyl and even alkylborane reagents of different reactivity can be used for coupling with aryl, alkenyl, alkynyl and some alkyl halides, offering very useful synthetic methods. The cross-coupling of aryl and heteroarylboronic acids with aryl and heterocyclic halides and triflates provide useful synthetic routes to various aromatic and heteroaromatic derivatives. Sometimes, the reaction proceeds in the... 

An easy and simple synthesis of different chiral fran -l-arenesulfonylamino-2-isoborneolsulfonylaminocyclohexane derivatives (41) has been reported.108 These ligands have proved to be excellent promoters for the catalytic enantioselective alkylation and arylation of ketones (up to 99% ee), very good for the alkenylation process, and modest for the allylation and alkynylation reactions. 

Alkenyl and alkynyl R4Pb and RePb2 compounds tend to be less stable thermally than alkyl analogs. Furthermore, they also exhibit poorer hydrolytic stability and stability to air. Thus, tetravinyllead is sensitive to water. The failure to successfully isolate tetraallyllead may be as much due to its hydrolytic and air instability as to its thermal instability. Alkyl and aryl derivatives which are substituted extensively with fluorine atoms also tend to be hydrolytically unstable, particularly... 

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