Transmetallation of β-allenyl silanes: efficient synthesis of dienyl chlorostannanes and chlorostibinesElectronic supplementary information (ESI) available: NMR spectra of compounds 1a and 2a. See http://www.rsc.org/suppdata/cc/b1/b111580b/
The reaction of 1-trimethylsilylbuta-2,3-diene with tin tetrachloride, antimonytrichloride or antimonypentachloride gave the corresponding buta-1,3-dien-2-yl halostannane or stibine derivatives; this ligand exchange was extended to other beta-allenylsilanes.
β-Trimethylsilyl allenes have been prepared in fair to good yields fromallylsilanes by successive dibromocarbene addition and rearrangement of the cyclopropylidenes. In the case of 3,6-bis(trimethylsilyl)cyclohexa-1,4-diene, insertion of dibromocarbene occurs in the silicon-carbon bond leading to α-bromobenzyltrimethylsilane.