Indium-Catalyzed [2 + 2] Cycloaddition of Allylsilanes to Internal Alkynones
摘要:
We have developed an indium-catalyzed [2 + 2] cydo-addition of allylsilanes to alkynones leading to selective cydobutenone formation. The resulting cydobutenones were readily converted to the oxidized products by Tamao-Fleming oxidation or the ring-opened products by an electrocyclic reaction.
The palladium-catalyzed reaction of γ-silylated allyl acetates with water in the presence of CsF induces a previously unprecedented 1,2-shift of a substituent on silicon to produce allylsilanes in situ. The catalytic activity of the palladium increased when using an electron-poor phosphine ligand possessing fluorinated substituents. Further investigation of the reaction revealed that the approximate
Regioselective synthesis of highly functionalized alkenylboronates by Cu-catalyzed borylation of propargylic silylalkynes
作者:Yeong Eun Kim、DingXi Li、Jaesook Yun
DOI:10.1039/c5dt00144g
日期:——
Highregioselectivity was achieved in the Cu(I)-catalyzed borylation of internal propargylic alkynes with a silyl substituent to afford multifunctionalized alkenylboron compounds. While both the silyl and propargylic substituents are known to act as directing groups, a N-heterocyclic carbene (NHC)–Cu complex furnished β-vinylboronate products (relative to Si) with high selectivity.
Alkynyl halides are reduced by chromium(II) chloride in DMF to give unisolable alkynylchromium compounds which add selectively to an aldehyde moiety without affecting the coexisting ketone group of the substrate.
作者:Shenghan Teng、Zhenguo Zhang、Bohan Li、Lanyang Li、Melinda Chor Li Tan、Zhenhua Jia、Teck‐Peng Loh
DOI:10.1002/anie.202311906
日期:2023.11.6
A novel type of silicon-containing alkynone reagents that target free thiols to produce the stable vinyl-sulfide linker under biocompatible conditions is reported. Besides simple aliphatic and aromatic thiols, this approach is also applicable to the labeling of thiols present in proteins, sugars and pharmaceuticals with full retention of silicon handles in most cases.