magnesium in tetrahydrofuran 1 h; Heating;

1: 1,4-Diiodobenzene With isopropylmagnesium chloride in tetrahydrofuran T=-30°C; 5.5 h; 2: ethyl orthosilicate; phenyl-1,4-bis(magnesium chloride) in tetrahydrofuran T=-30 - 20°C; 49 h;