The reactions of trialkylstannane anions R 3 Sn− with arylstannanes ArSnR 3′ have been investigated; trialkylstannane anions with arylstannanes at 50° C gave substitution products ArSnR 3 in good yields. Most of these substitution products are diverted to reduction products ArH when t-butylamine for trapping free anionoids is present in the reaction mixture. These results are consistent with an initial tin–alkali metal exchange or an ...