Aryl magnesium halides

Schliiter et al. [161 were the first to describe coupling of aromatic compounds containing aryl-magnesium halide and aryl halide functions, catalyzed by Ni(0) compounds. Here, the authors adapted the principle of attaching solublizing side chains (in the 2- and 5- positions) and arrived at soluble and processable... 

The reaction of aryl magnesium halides with perfluorohalogenosulfenyl chlorides takes place under considerably milder conditions 47, 148) ... 

Except in one case, all reactions of 2-pyrones with nucleophiles use alkyl or aryl magnesium halides. 

In the majority of cases, organolithium compounds and Grignard reagents contain polarized but covalent carbon—metal bonds. Lithioalkanes, -alkenes, and -aromatics, on the one hand, and alkyl, alkenyl, and aryl magnesium halides, on the other hand, are therefore formulated with a hyphen between the metal and the neighboring C atom. Only lithiated alkynes and alkynyl Grignard reagents are considered to be ionic—that is, species with carbon, metal bonds similar to those in LiCN or Mg(CN)2. 

Grignard reagent produces greenish blue luminescence in its reaction with chloropicrin or on its oxidation by air. Only aryl magnesium halides in which Magnesium atom is attached to one unsaturated carbon atom exhibit chemiluminescence s in solution while in solid state, both alkyl and aryl magnesium halides show this phenomenon. 

As in the Grignard reaction we may use any aliphatic aldehyde, ketone, ester or acid chloride, or an aryl compound of the same type and also, we may use either alkyl magnesium halides or aryl magnesium halides the synthesis makes possible the preparation of practically any desired secondary or tertiary alcohol either aliphatic or aromatic. Also if formaldehyde, in the form of its polymer, tri-oxy methylene, is used in the second reaction we will obtain primary alcohols. In the third reaction formic acid esters yield secondary instead of tertiary alcohols. These syntheses of alcohols by the Grignard reaction give us an idea of its importance in synthetic work. 

Whereas the preparation of aliphatic aluminum compounds from appropriate element alkyls and aluminum halides is now of interest only in special cases (see Sections II,A,3 and IV,B), the route to aryl aluminum compounds from aryl magnesium halides and aluminum halides or from either aluminum or trialkylamine alanes and mercury diaryls is still useful (174, 48). 

In general, zinc reagents are prepared by a transmetallation reaction of aryllithium or aryl-magnesium halides with zinc halides at low temperature (—78°C). The same approach can be used for heteroarenes in the absence of incompatible substituents, but has been little applied to pyrimidines. 

Alkyl and aryl magnesium halides (Grignard reagents, represented by the formula RMgX) are extremely well known on account of their uses in synthetic organic chemistry (see further reading list for this chapter). The general... 

Of the many organometallic compounds, only Grignard reagents are used for formation of C-N bonds. Alkyl- and aryl-magnesium halides undergo various types of reaction with nitrogen compounds,1216 but few of these have major importance. 

When a tertiary alcohol is formed by a Grignard reaction, the derived olefin is often easily obtained by warming the Grignard addition compound without isolation of the alcohol after treatment of the alkyl- or aryl-magnesium halide with the carbonyl compound and removal of the solvent, the residue is heated for a short time, whereupon the olefin distils off.12 In this way, for instance,... 

The interaction of aryl magnesium halides and bismuth halides, the yield being about 60 per cent. ... 

Other reagents that open the epoxide ring with substitution, to give the useful derivatives indicated in parentheses, include phenols (phenyl ethers) (81) y carboxylic acids (esters) (8 ), hydrogen sulfide in the presence of barium hydroxide (thiols) (82), sodium methyl mercaptide (methyl thio-ethers) (83), dipotassium hydrogen phosphate or dibenzylphosphoric acid (phosphate esters) (84), alkyl or aryl magnesium halides (halodeoxysugars)... 

Alkyl and aryl magnesium halides react with isocyanates to give the substituted carboxylic acid amides 263 after hydrolysis . 

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