Palladium-Catalyzed Homo-Coupling of Heteroarylsulfoniums via Borylation/Suzuki-Miyaura Coupling Sequence
摘要:
Palladium-catalyzed homo-coupling of heteroaryldimethylsulfoniums proceeds in the presence of bis(pinacolato)diboron and a base to yield biheteroaryls. The homo-coupling involves palladium-catalyzed borylation and the subsequent Suzuki-Miyaura coupling. As the sulfoniums were able to be prepared in situ from the corresponding heteroaryl sulfides and methyl triflate, one-pot transformations of heteroaryl sulfides into the homo-coupling products were executed. Furthermore, a facile synthesis of a highly substituted 2,2'-bibenzofuran was accomplished with a combination of Pummerer-type synthesis of 2-benzofuryl sulfide and the present homo-coupling.
Generation of Organozinc Reagents from Arylsulfonium Salts Using a Nickel Catalyst and Zinc Dust
作者:Kodai Yamada、Tomoyuki Yanagi、Hideki Yorimitsu
DOI:10.1021/acs.orglett.0c03782
日期:2020.12.18
powder under nickel catalysis via the selective cleavage of the sp2-hybridized carbon–sulfur bond to produce salt-free arylzinc triflates undermildconditions. This zincation displays superb chemoselectivity and thus represents a protocol that is complementary or orthogonal to existing methods. The generated arylzincreagents show both high reactivity and chemoselectivity in palladium-catalyzed and copper-mediated
Palladium-Catalyzed Arylthiolation of Alkynes Enabled by Surmounting Competitive Dimerization of Alkynes
作者:Daisuke Uno、Keisuke Nogi、Hideki Yorimitsu
DOI:10.1021/acs.orglett.9b03056
日期:2019.10.18
By overcoming the unwanted catalytic dimerization of terminal alkynes, palladium-catalyzed carbothiolation of alkynes with heteroaryl sulfides has been accomplished to provide the corresponding β-heteroaryl alkenyl sulfides with high regio- and stereoselectivity. The key for the preferential arylthiolation is the use of arylsulfanyl segments, instead of alkylsulfanyl, for smooth C(heteroaryl)-SR1 bond
Palladium‐Catalyzed Insertion of Isocyanides into the C−S Bonds of Heteroaryl Sulfides
作者:Shinya Otsuka、Keisuke Nogi、Hideki Yorimitsu
DOI:10.1002/anie.201802369
日期:2018.5.28
Insertion of tert‐butyl isocyanide into the C(sp2)−S bonds of heteroaryl sulfides is catalyzed by a palladium diphosphine complex. Thioimidates generated through this reaction could be readily hydrolyzed under acidic conditions to yield the corresponding thioesters, which are of synthetic use. This insertion is useful because starting heteroaryl sulfides were readily prepared by either conventional
Palladium-catalyzed carbothiolation of terminalalkynes with azolyl sulfides affords various 2-(azolyl)alkenyl sulfides with perfect regio- and stereoselectivities. The present addition reaction proceeded through a direct cleavage of carbon–sulfur bonds in azolyl sulfides. The resulting adducts that are useful intermediates in organic synthesis are further transformed to multisubstituted olefins containing