An efficient synthetic method for the preparation of multisubstituted furans, thiophenes, and pyrroles using ynolates was developed. This novel formal [4 + 1] annulation by C2-C3 and C3-C4 bond formations includes cycloaddition, cyclization, decarboxylation, and dehydration as key steps.
Palladium-Catalyzed Fluoride-Free Cross-Coupling of Intramolecularly Activated Alkenylsilanes and Alkenylgermanes: Synthesis of Tamoxifen as a Synthetic Application
作者:Kenji Matsumoto、Mitsuru Shindo
DOI:10.1002/adsc.201100627
日期:2012.3
intramolecular hypercoordination of a carboxylic acid is a powerful activation strategy for the palladium‐catalyzed cross‐coupling reaction of trialkyl(vinyl)silanes and trialkyl(vinyl)germanes under fluoride‐free conditions. Z‐β‐Trialkylsilyl‐ and Z‐β‐trialkylgermylacrylic acids, synthesized stereoselectively by olefination with ynolates, are highly stable and useful reagents for cross‐coupling with a variety
The Behaviors of Metal Acetylides with Dinitrogen Tetroxide
作者:Christopher?J. Woltermann、Harold Shechter
DOI:10.1002/hlca.200590020
日期:2005.2
total loss of metal ion. Loss of metal ions from metallo acetylide radical cations and H-abstraction by non-caged acetylenyl radicals will give terminal acetylenes. The principal reactions (75–100%) of heavy metal acetylides phenyl(trimethylstannyl)acetylene (44) and bis(phenylacetylenyl)mercury (47) with 2 are directed nitrosative additions (NO+) and loss of metal ions to give nitroso(phenyl)ketene (27)
Asymmetric inverse electron-demand 1,3-dipolar cycloaddition of ynolates with a chiral nitrone derived from l-serine leading to β-amino acid derivatives
作者:Mitsuru Shindo、Keiko Ohtsuki、Kozo Shishido
DOI:10.1016/j.tetasy.2005.07.023
日期:2005.8
Asymmetric 1,3-dipolarcycloaddition of lithium ynolates with a nitronederivedfrom Garner’s aldehyde is described. The cycloadducts, 5-isoxazolidinones, were obtained in good yields with high diastereoselectivity. Alkylation of the intermediates, the 5-isoxazolidinone enolates, was also achieved with high selectivity, the products of which were converted into the enantiomerically pure β-amino acids
reports the synthesis of cyclobutene derivatives in good yields via the [2 + 2] cycloaddition between lithium ynolates and α,β-unsaturated carbonyls. The ynolates are generated fromα,α,α-tribromomethyl ketones and tert-butyl lithium via a simple and novel method, which does not produce any harmful byproducts, such as lithium alkoxide, which induces a polymerization reaction with α,β-unsaturated carbonyls