“…As imilar Cu-catalyzed method using selenium and (N-methyl-2-pyrrolidone) (NMP) instead of sulfur and DMF [18a] allowed conversion of 6b and 9 into benzo [1,2- (15). [27] Atwofold iodine-lithium exchange/electrophilic trapping sequence proved effective for the preparation of germanium-and phosphoryl-bridged p-teraryls 12 and 13, [15a, 28] respectively.T he latter product was obtained as as eparable mixture of syn-a nd anti-isomers.B esides the heteroatom-bridged p-teraryls,t he Pd-catalyzed reaction of 6b with 5-decyne,u sing Wus conditions, [29] resulted in atwofold annulation to afford benzo[k]tetraphene derivative 14.Single-crystal X-ray diffraction analysis was performed for all of these ladder-type products except anti-13,w hich invariably demonstrated high levels of coplanarity of their Scheme 3. a) Conversiono f2',5'-diiodo-p-terphenyl derivatives 4a-4d to 2,2',2'',5'-tetraiodo-p-terphenyl derivatives 6a-6d,a nd b) conversion of 2,5-bis(2-iodophenyl)thiophene 7 to 3,4-diiodo-2,5-bis(2-iodophenyl)thiophene 9.Reaction conditions: i) mCPBA (3 equiv), TfOH (6 equiv), CH 2 Cl 2 ,RT, 2h;i i) CuI (20 mol %), L1 (40 mol %), [(nBu) 4 N]I (4 equiv), MeCN, 60 8 8C, 24 h. Inset:O RTEP drawing of 5b (thermal ellipsoids set at 50 %p robability), whereby hydrogen atoms, counteranions, and solvent molecules were omitted for clarity. [27] Atwofold iodine-lithium exchange/electrophilic trapping sequence proved effective for the preparation of germanium-and phosphoryl-bridged p-teraryls 12 and 13, [15a, 28] respectively.T he latter product was obtained as as eparable mixture of syn-a nd anti-isomers.B esides the heteroatom-bridged p-teraryls,t he Pd-catalyzed reaction of 6b with 5-decyne,u sing Wus conditions, [29] resulted in atwofold annulation to afford benzo[k]tetraphene derivative 14.Single-crystal X-ray diffraction analysis was performed for all of these ladder-type products except anti-13,w hich invariably demonstrated high levels of coplanarity of their Scheme 3. a) Conversiono f2',5'-diiodo-p-terphenyl derivatives 4a-4d to 2,2',2'',5'-tetraiodo-p-terphenyl derivatives 6a-6d,a nd b) conversion of 2,5-bis(2-iodophenyl)thiophene 7 to 3,4-diiodo-2,5-bis(2-iodophenyl)thiophene 9.Reaction conditions: i) mCPBA (3 equiv), TfOH (6 equiv), CH 2 Cl 2 ,RT, 2h;i i) CuI (20 mol %), L1 (40 mol %), [(nBu) 4 N]I (4 equiv), MeCN, 60 8 8C, 24 h. Inset:O RTEP drawing of 5b (thermal ellipsoids set at 50 %p robability), whereby hydrogen atoms, counteranions, and solvent molecules were omitted for clarity.…”