Scheme 5.

Synthesis of 29 as backbone building block B₂. Reagents and conditions: a) CPDIPS‐acetylene, (Ph₃P)₂PdCl₂, CuI, THF: piperidine 3:1, room temp., 1 h, quant. b) NIS, DMSO, room temp., 1 h, 85 % 22, 1.9 % 23, 1.6 % 24 and 4.9 % 25. c) 3‐bromophenylboronic acid, K₂CO₃, (Ph₃P)₂PdCl₂, DME: EtOH: H₂O 4:1:1, 80 °C, 12 h, 84 %. d) pTsOH⋅H₂O, MeCN, NaNO₂, KI, MeCN, H₂O, 10 °C→room temp., 16 h, 82 %. e) 2‐aminophenylboronic acid hydrochloride, K₂CO₃, (Ph₃P)₂PdCl₂, DME: EtOH: H₂O 4:1:1, 80 °C, 12 h, 97 %. f) pTsOH⋅H₂O, MeCN, NaNO₂, KI, MeCN, H₂O, 10 °C→room temp., 2 h, 85 %.