Phenyl isocyanide, 2,6-dimethyl

The reaction of [p-MeC6H4C(NSiMe3)2]2Ta( = CH2)CH3 with 2,6-dimethyl-phenyl isocyanide afforded an f/ -ketenimine complex (Scheme 118). Carbon-sulfur cleavage reactions produced tantalum thioformaldehyde and tantalum sulfido complexes. ... 

Finally, a reaction should be mentioned in which a nucleophile gives support to another reacting species without appearing in the final product. Diphenyl cyclopropenone interacts with 2,6-dimethyl phenyl isocyanide only in the presence of tri-phenylphosphine with expansion of the three-ring to the imine 344 of cyclobutene-dione-1,2229,230 Addition of the isocyanide is preceded by formation of the ketene phosphorane 343, which can be isolated in pure formss 231 it is decomposed by methanol to triphenyl phosphine and the ester 52. 

Titanium derivatives containing carbazole (cb) ligands have been isolated and studied. Reaction of Ti(CH2SiMe3)4 with carbazole yields the alkylidene-bridged dimer [Ti(/i-CHSiMe3)(cb)2]2 (Scheme 106). A singlet at 8 14.75 is observed in the 1H NMR spectrum of the alkylidene complex. The reaction of this compound with 2,6-dimethyl-phenyl isocyanide leads to titanium derivatives containing new carbon-carbon bonds (Section 4.05.2.3).109,110... 

TABLE 2.1 Av of 2,6-dimethyl-phenyl Isocyanide Pt(ll) derivatives as a function of the different ligands 2a-h... 

Other interesting multicomponent sequences utilizing isocyanides have been elaborated by Nair and coworkers. In a recent example, this group exploited the nucleophilic nature of the isocyanide carbon, which allows addition to the triple bond of dimethyl acetylenedicarboxylate (DMAD) (9-90) in a Michael-type reaction (Scheme 9.19) [59]. As a result, the 1,3-dipole 9-91 is formed, which reacts with N-tosylimines as 9-92 present in the reaction vessel to give the unstable iminolactam 9-93. Subsequently, this undergoes a [1,5] hydride shift to yield the isolable aminopyrroles 9-94. In addition to N-tosylimine 9-92 and cyclohexyl isocyanide (9-89), substituted phenyl tosylimines and tert-butyl isocyanide could also be used here. 

C2H,N, Pyridine, 3,5-dimethyl-palladium complex, 26 210 CbHsNO, Benzoyl isocyanide chromium com-C HbO, Ethanone, 1-phenyl-manganese complex, 26 156-158 CBH, 02, Methyl benzoate chromium complex, 26 32 C H i, o-Xylylene magnesium complex, 26 147 ChH P, Phosphine, dimethylphenyl-iron complex, 26 61 ruthenium complex, 26 273 ChH12, 1,5-Cyclooctadiene iridium complex, 26 122 ruthenium complexes, 26 69-72, 253-256 ChH OjPS, 2-Butenedioic acid, 2-(dimethylphosphinothioyl)-dimethyl ester, manganese complex, 26 163... 

IX dimethyl ester Pyz = Pyrazine RImH = Imidazole with an R substituent on one of the carbon atoms RNC = Alkyl or aryl isocyanide (isonitrile) RNO = alkyl or aryl nitroso compound RPy = Substituted pyridine RTPP = 7 -phenyl substituted tetraphenylporphyrin TCeTPP = Tetra-/3,/3 -tetramethylenetetraphenyl-porphyrin TMINP = Tetrakis(o-(methylisonicotinamidophenyl)porphyrin) T(o-M)PyP = Tetrakis(methyl-o-pyridinium)porphyrin ... 

MgS04) and concentrated under reduced pressure to give 5.8 g of crude (+)-cis-isocyanide as a yellow solid. Column chromatography (Si02 EtOAc/hexane, 2 1) gave 4.52 g (17.0 mmol, 69%) of analytically pure (+)-ds-2-(isocyanomethyl)-5,5-dimethyl-2-oxo-4-phenyl-l,3,2-dioxaphosphorinane 1618 as transparent needles mp 145 °C. 

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