in not given (N2); react. of I2 with germanium complex; not isolated, detected by NMR;

in tetrahydrofuran byproducts: pentamethylcyclopentadiene; (N2); addn. of a soln. of catechol deriv. in THF to a soln. of tin complex in THF at room temp., stirring for 2 h; evapn., washing with Et2O, detected by NMR;