This work describes a base-mediated borylsilylation of benzylic ammoniumsalts to synthesize geminal silylboronates bearing benzylic proton under mild reaction conditions. Deaminative silylation of aryl ammoniumsalts was also achieved in the presence of LiOtBu. This strategy which is featured with high efficiency, mild reaction conditions, and good functional group tolerance provides efficient routes
这项工作描述了碱介导的苄基铵盐的硼基甲硅烷基化,以在温和的反应条件下合成带有苄基质子的孪晶甲硅烷基硼酸酯。在 LiO t Bu存在下也实现了芳基铵盐的脱氨基甲硅烷基化。该策略具有高效、反应条件温和、官能团耐受性好的特点,为胺类的后期官能化提供了有效途径。
Highly Active Palladium Catalysts Supported by Bulky Proazaphosphatrane Ligands for Stille Cross-Coupling: Coupling of Aryl and Vinyl Chlorides, Room Temperature Coupling of Aryl Bromides, Coupling of Aryl Triflates, and Synthesis of Sterically Hindered Biaryls
作者:Weiping Su、Sameer Urgaonkar、Patrick A. McLaughlin、John G. Verkade
DOI:10.1021/ja0450096
日期:2004.12.1
R' = i-Bu, 1; R = Bz, R' = i-Bu, 3; R = R' = Bz, 4] for palladium-catalyzed Stille reactions of aryl chlorides is described. Catalysts derived from ligands 1 and 4 efficiently catalyze the coupling of electronically diverse aryl chlorides with an array of organotin reagents. The catalyst system based on the ligand 3 is active for the synthesis of sterically hindered biaryls (di-, tri-, and tetra-ortho
electron donor (p-NMe2C6H4 group) and acceptor (p-NO2C6H4 group) unit was synthesized and their photophysical properties were investigated. By using aromatic heterocycles (thiophene, furan, pyrrole) as the π-linkers between the donor and acceptor units, significant effects on the bathochromic shift and enhancement of the two-photonabsorption wavelength and the two-photonabsorptioncross-sections were
2-(4-N,N-dimethylaminophenyl) heterocycles are smoothly obtained from the photolysis of 4-chloro-N,N-dimethylaniline in acetonitrile in the presence of furan, pyrrole, thiophene and some of their methyl derivatives bearing a free α-position. With 2,5-dimethyl heterocycles the arylation occurs with equal efficiency in the β position. In the case of furan, when the irradiation is carried out in methanol