29488-24-2Relevant articles and documents
Pd-Catalyzed Dearomative Three-Component Reaction of Bromoarenes with Diazo Compounds and Allylborates
Komatsuda, Masaaki,Kato, Hiroki,Muto, Kei,Yamaguchi, Junichiro
, p. 8991 - 8995 (2019)
A catalytic dearomative three-component reaction of bromoarenes with TMS-diazomethane and allyl borate was developed. The key of this assembling reaction is the use of a diazo compound to generate a Pd-π-benzyl intermediate through a Pd-carbene species. T
Decarboxylative Bromination of Heteroarenes: Initial Mechanistic Insights
Patel, Pritesh R.,Henderson, Scott H.,Roe, Mark S.,Honey, Mark A.
supporting information, p. 1603 - 1607 (2020/09/09)
After an initial report from our laboratory describing metal-free decarboxylative halogenation of various azaheteroarenes, we set out to investigate the possible mechanism by which this chemistry occurs. Evidence from this mechanistic investigation sugges
A Rational Design of Highly Controlled Suzuki-Miyaura Catalyst-Transfer Polycondensation for Precision Synthesis of Polythiophenes and Their Block Copolymers: Marriage of Palladacycle Precatalysts with MIDA-Boronates
Seo, Kyeong-Bae,Lee, In-Hwan,Lee, Jaeho,Choi, Inho,Choi, Tae-Lim
supporting information, p. 4335 - 4343 (2018/04/05)
Herein, we report a highly efficient Suzuki-Miyaura catalyst-transfer polycondensation (SCTP) of 3-alkylthiophenes using bench-stable but highly active Buchwald dialkylbiarylphospine Pd G3 precatalysts and N-methylimidodiacetic (MIDA)-boronate monomers. Initially, the feasibility of the catalyst-transfer process was examined by screening various dialkylbiarylphospine-Pd(0) species. After optimizing a small molecule model reaction, we identified both RuPhos and SPhos Pd G3 precatalysts as excellent catalyst systems for this purpose. On the basis of these model studies, SCTP was tested using either RuPhos or SPhos Pd G3 precatalyst, and 5-bromo-4-n-hexylthien-2-yl-pinacol-boronate. Poly(3-hexylthiophene) (P3HT) was produced with controlled molecular weight and narrow dispersity for a low degree of polymerization (DP) only, while attempts to synthesize P3HT having a higher DP with good control were unsuccessful. To improve the control, slowly hydrolyzed 5-bromo-4-n-hexylthien-2-yl-MIDA-boronate was introduced as a new monomer. As a result, P3HT and P3EHT (up to 17.6 kg/mol) were prepared with excellent control, narrow dispersity, and excellent yield (>90%). Detailed mechanistic investigation using 31P NMR and MALDI-TOF spectroscopy revealed that both fast initiation using Buchwald precatalysts and the suppression of protodeboronation due to the protected MIDA-boronate were crucial to achieve successful living polymerization of P3HT. In addition, a block copolymer of P3HT-b-P3EHT was prepared via SCTP by sequential addition of each MIDA-boronate monomer. Furthermore, the same block copolymer was synthesized by one-shot copolymerization for the first time by using fast propagating pinacol-boronate and slow propagating MIDA-boronate.