Isonitrile, insertion into aryl

Isonitriles 592 undergo a palladium mediated insertion into aryl bromides 593 followed by intramolecular cycliza-tion upon reaction with the pendant alcohol to afford isochromans that feature a C-l imidate moiety 594 (Equation 245) <2004TL6995>. 

Substituted diazomethanes, such as diazoacetic ester, react with some arylcopper compounds 34, 255) by carbene insertion into the C—Cu bond [Eq. (34)]. Isonitriles are also reported 281d) to insert into an aryl—Cu bond [Eq. (35)] in benzene solution at 25°C. 

The pincer like diamino functionalised carbene ligand stabilises the group 4 metal sufficiently to perform a few very interesting insertion reactions with the M-Me bond. The reactions were performed with the hafnium rather than the zirconium complexes [113]. Small molecules used for these insertion reactions include isonitriles (aryl and alkyl) and CO (see Figure 4.36). Reaction of the hafnium carbene dimethyl complex with xylyl-isonitrile results in addition of this excellent donor ligand and subsequent insertion into the Hf-Me... 

Although CO and alkenes are the most prominent substrates participating in migratory insertions, a variety of additional molecules are also susceptible to undergo such reactions. " " For example, both alkyl and aryl isonitriles (RNC) readily insert into M-C or M-H bonds to generate iminoacyl or formimidoyl derivatives, respectively... 

Insertion of isonitriles and carbenoids into the B-B and B-Si bonds have recently been developed as a method for synthesizing geminal bis(boryl) and boryl-silyl compounds (Scheme 24). The insertion of alkyl and aryl isonitriles into the B-Si bond proceeded at room temperature to provide monomeric (boryl)(silyl)imines 227.388,389 Alkylidene... 

The tetrameric o-(dimethylaminomethyl)phenylcopper, which is similar to (III) and probably possesses the same structural features, forms monomeric complexes with l,2-bis(diphenylphosphino)ethane and -ethylene but not with triphenylphosphine (281e). Insertion of an isonitrile into the aryl—Cu bond occurs rather than formation of a complex (281d). The new copper compound is dimeric in benzene, and a six-membered ring structure involving heteroatom coordination bonding as in (V) is proposed. Triphenylphosphine breaks down the dimer (V)... 

Insertion of isonitriles into Si-Si bonds takes place in the presence of palladium catalysts to give bis(silyl)imines 85, which show characteristic UV absorbance around 400 nm arising from n-Ji transition (Eq.43) [79]. Aryl and alkyl isonitriles except for tertiary alkyl isonitrile give the corresponding N-substituted imines. 

Recent progress in polymerization of isonitriles with organopalladium(II) complexes is shown below. Although reactions of aryl isonitriles with -ethynediyl-dipalladium(II) 6 and a related Pd-Pt heterodinuclear complex 7 at room temperature (r.t.) did not afford poly(isonitrile)s, selective double insertion of the isonitrile into the Pd—C bond (giving 8) or coordination of the isonitrile to the metal (giving 9) occurred (Scheme Polymer-... 

Square planar / -complexes of rhodium are known for engaging in catalytic cycles based on oxidative addition chemistry. A recently developed example is reaction (5), involving insertion of an isonitrile into an aryl C —H bond. " Initial dissociation of phosphine is likely, providing 14-electron [RhCl(L)(CNR)]. The [Cp Re(CO)L] fragment was very readily produced... 

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