Sugita Hajime, Kamigawara Takeru, Miyazaki Sou, Shimada Ryusuke, Katoh Takayoshi, Ohta Yoshihiro, Yokozawa Tsutomu
Department of Materials and Life Chemistry, Kanagawa University, Rokkakubashi, Kanagawa-ku, Yokohama, 221-8686, Japan.
Chemistry. 2023 Aug 21;29(47):e202301242. doi: 10.1002/chem.202301242. Epub 2023 Jul 26.
Intramolecular catalyst transfer on benzoheterodiazoles was investigated in Suzuki-Miyaura coupling reactions and polymerization reactions with Bu PPd precatalyst. In the coupling reactions of dibromobenzotriazole, dibromobenzoxazole, and dibromobenzothiadiazole with pinacol phenylboronate, the product ratios of monosubstituted product to disubstituted product were 0/100, 27/73, and 89/11, respectively, indicating that the Pd catalyst undergoes intramolecular catalyst transfer on dibromobenzotriazole, whereas intermolecular transfer occurs in part in the case of dibromobenzoxazole and is predominant for dibromobenzothiadiazole. The polycondensation of 1.3 equivalents of dibromobenzotriazole with 1.0 equivalent of para- and meta-phenylenediboronates afforded high-molecular-weight polymer and cyclic polymer, respectively. In the case of dibromobenzoxazole, however, para- and meta-phenylenediboronates afforded moderate-molecular-weight polymer with bromine at both ends and cyclic polymer, respectively. In the case of dibromobenzothiadiazole, they afforded low-molecular-weight polymers with bromine at both ends. Addition of benzothiadiazole derivatives interfered with catalyst transfer in the coupling reactions.