Reactions of neodymium(II) iodide with organohalides

The reactions of NdI2 (1) with aryl halides, PhX (X = Cl, Br, I), in THF afford benzene and a minor amount of biphenyl. Benzyl chloride under the same conditions yields 1,2-diphenylethane, toluene and PhCH2I due to Cl/I exchange. Alkyl halides C7H15Br and cyclo-C6H11Cl are reduced to the corresponding hydrocarbons. t-BuCl affords a mixture of isobutane/isobutylene. Chlorotrimethylsilane is converted into Me3SiH, hexamethyldisilane and Me3SiO(CH2)4CH3 in 10%, 8% and 31% yields respectively at room temperature but 1%, 2% and 88% yields at −60 °C. In benzene, the interaction of 1 with benzyl chloride proceeds at 80 °C to give diphenylmethane in 66% yield. Without solvent the same reaction leads to formation of the oligomers PhCH2(p-C6H4CH2)nC6H4CH2Cl. Heating 1 in benzene with n-BuCl or cyclo-C6H11Cl affords mono- and disubstituted products, RC6H5 and 1,4-R2C6H4. The n-Bu groups in the reaction transform into sec-Bu isomers. Iodobenzene, bromobenzene, Me3SiCH2Cl and Me3SiCl are inert towards 1 in benzene.

Graphical abstractThe reactions of NdI2 with organohalides PhX, C7H15X, cyclo-C6H11X, t-BuX (X = Cl, Br, I) in THF afford mainly the respective hydrocarbons R–H. Chlorotrimethylsilane is converted into Me3SiH, Me3SiSiMe3 and Me3SiO(CH2)4CH3. The interactions of NdI2 with alkyl halides in benzene result in alkylation of the solvent to give the mono- and disubstituted products R-Ph and R2C6H4. Treatment of benzyl chloride by NdI2 without solvent causes the oligomer PhCH2(p-C6H4CH2)28C6H4CH2Cl formation.Figure optionsDownload full-size imageDownload as PowerPoint slide