35664-72-3Relevant academic research and scientific papers
Pd-Catalyzed Cyclization of Alkynyl Norbornene Derivatives for the Synthesis of Benzofused Heteroarenes
Kwak, Hayeon,Kang, Eunsu,Song, Jae Yeong,Kang, Geunhee,Joo, Jung Min
supporting information, p. 4883 - 4888 (2021/09/09)
Modular approaches, which allow a systematic variation of heteroaromatic cores and substituents, are crucial for the development of heteroaromatic drug candidates and organic functional materials. A new strategy involving the cyclization of heteroarenes tethered with alkynes through a norbornene bridge was developed. The precursors were readily prepared by a three-component coupling process of heteroaryl halides, norbornadiene, and terminal alkynes. The Pd catalytic system derived from Pd(OAc)2 and 2-(pyrazol-1-yl)pyridine transformed a variety of five-membered heteroarenes to the corresponding benzofused products, including (di)benzothiophene, indazole, carbazole, indole, and benzofuran, with aryl and alkyl substituents at the C4(C7) position. During the cyclization process, the norbornene ring underwent a retro-Diels-Alder reaction, serving as an acetylene synthon. This approach was used to synthesize naphthalene derivatives from electron-rich arenes, demonstrating its versatility in the annulation of (hetero)aromatic rings. (Figure presented.).
Zinc-gold cooperative catalysis for the direct alkynylation of benzofurans
Li, Yifan,Waser, Jerome
supporting information, p. 1763 - 1767 (2013/10/22)
The direct alkynylation of benzofurans was achieved for the first time using the hypervalent iodine reagent 1-[(triiso-propylsilyl)ethynyl]-1,2- benziodoxol-3(1H)-one (TIPS-EBX) based on the cooperative effect between a gold catalyst and a zinc Lewis acid. High selectivity was observed for C2-alkynylation of benzofurans substituted with alkyl, aryl, halogen and ether groups. The reaction was also successful in the case of the more complex drug 8-methoxypsoralen (8-MOP).
An isomerization-ring-closing metathesis strategy for the synthesis of substituted benzofurans
Van Otterlo, Willem A.L.,Morgans, Garreth L.,Madeley, Lee G.,Kuzvidza, Samuel,Moleele, Simon S.,Thornton, Natalie,De Koning, Charles B.
, p. 7746 - 7755 (2007/10/03)
Twelve substituted benzofurans were synthesized from their corresponding substituted 1-allyl-2-allyloxybenzenes using ruthenium-mediated C- and O-allyl isomerization followed by ring-closing metathesis.
