The orientation of substitution in metallation of dimethylaminomethyl-, hydroxymethyl- and diphenylphospino-cymantrenes

Dimethylaminomethyl- and hydroxymethyl-cymantrenes, when treated with n-butyllithium, are selectively metallated in the 2(5) position of the Cp ring and are converted into 1,2-disubstituted derivatives of cymantrene by subsequent treatment with electrophilic reagents. Similar reactions in the case of diphenylphosphinocymantrene result in a selective preparation of 1,3-disubstituted derivatives. The metallation orientation is established by chemical methods and NMR-LIS (lanthanide-induced shift) techniques. A full assignment of signals in the PMR and 13 C NMR spectra of the studied monosubstituted cymantrene derivatives has been effected.