A sequential procedure for the synthesis of 2,5-disubstituted thiazoles from terminal alkynes, sulfonyl azides, and thionoesters is reported. A copper(I)-catalyzed 1,3-dipolar cycloaddition of terminal alkynes with sulfonyl azides affords 1-sulfonyl-1,2,3-triazoles, which then react with thionoesters in the presence of a rhodium(II) catalyst. The resulting 3-sulfonyl-4-thiazolines subsequently aromatize
Programmed synthesis of arylthiazoles through sequential C–H couplings
作者:Satoshi Tani、Takahiro N. Uehara、Junichiro Yamaguchi、Kenichiro Itami
DOI:10.1039/c3sc52199k
日期:——
A programmed synthesis of privileged arylthiazoles via sequential C–Hcouplings catalyzed by palladium or nickel catalysts has been accomplished. This versatile protocol can supply all possible arylthiazole substitution patterns (2-aryl, 4-aryl, 5-aryl, 2,4-diaryl, 2,5-diaryl, 4,5-diaryl, and 2,4,5-triaryl) from an unfunctionalized thiazole platform by 11 distinct synthetic routes. We have generated
Oxidative Biaryl Coupling of Thiophenes and Thiazoles with Arylboronic Acids through Palladium Catalysis: Otherwise Difficult C4-Selective CH Arylation Enabled by Boronic Acids
It adds up to 4! Thiophenes and thiazoles can be arylated in the 4‐ rather than the expected 5‐position in a new CH functionalization reaction (see scheme; TEMPO: 2,2,6,6‐tetramethylpiperidine‐N‐oxyl). The boronicacid proved to be the key to achieving the otherwisedifficult C4 selectivity. The method was applied to a concise synthesis of a key pharmacological structure with potential for treatment
Pd nanoparticle-silica nanotubes (Pd@SNTs) as an efficient catalyst for Suzuki–Miyaura coupling and sp2 C–H arylation in water
作者:Ginam Park、Sanghee Lee、Sang Jun Son、Seunghoon Shin
DOI:10.1039/c3gc41672k
日期:——
Silica nanotubes (SNTs) functionalized with Pd-NPs on the inner surface performed as efficient nano-reactors for CâC coupling in water; the nano-confinement offers minimized leaching of Pd and yet efficient mass transfer for SuzukiâMiyaura coupling and CâH arylation of thiazoles in water with very high TON.
practical Cu-catalyzed aerobicoxidativesynthesis of thiazoles was developed. This chemistry for the first time achieved thiazole construction from simple aldehydes, amines, and element sulfur through multiple Csp3–H bond cleavage processes. Molecular oxygen was used as a green oxidant in this oxidative protocol. The substrate scope is broad with the tolerance of aliphatic amines. The mechanistic study