Large‐Scale Synthesis of a Niche Olefin Metathesis Catalyst Bearing an Unsymmetrical N‐Heterocyclic Carbene (NHC) Ligand and its Application in a Green Pharmaceutical Context
large‐scale synthesis of known Ru olefinmetathesis catalyst VII featuring an unsymmetrical N‐heterocyclic carbene (NHC) ligand with one 2,5‐diisopropylphenyl (DIPP) and one thiophenylmethylene N‐substituent is reported. The optimised procedure does not require column chromatography in any step and allows for preparation of up to 0.5 kg batches of the catalyst from simple precursors. The application profile
Ruthenium Olefin Metathesis Catalysts with N-Heterocyclic Carbene Ligands Bearing <i>N</i>-Naphthyl Side Chains
作者:Ludovic Vieille-Petit、Hervé Clavier、Anthony Linden、Sascha Blumentritt、Steven P. Nolan、Reto Dorta
DOI:10.1021/om9009697
日期:2010.2.22
second-generation ruthenium-based olefinmetathesis catalysts bearing N-naphthyl-substituted N-heterocyclic carbene (NHC) ligands have been prepared and fully characterized. By reaction with the appropriate NHC, these complexes are readily accessible in one synthesis step from the commercially available first-generation precursors [RuCl2(═CHPh)(PCy3)2] (Grubbs I, GI) or [RuCl2(═CH-o-iPrO-Ph)(PCy3)] (Hoveyda−Grubbs
Calcium-Catalyzed Friedel-Crafts Alkylation at Room Temperature
作者:Meike Niggemann、Matthias J. Meel
DOI:10.1002/anie.200907227
日期:2010.5.10
A novel calcium catalyst was found to efficiently functionalize electron‐rich arenes with secondary and tertiary benzylic, propargylic, and allylic alcohols under very mild reaction conditions. The new catalyst system significantly enlarges the scope of the reaction, which was previously limited except for the few examples with secondary benzylicalcohols.
HFIP Solvent Enables Alcohols To Act as Alkylating Agents in Stereoselective Heterocyclization
作者:Yuxiang Zhu、Ignacio Colomer、Amber L. Thompson、Timothy J. Donohoe
DOI:10.1021/jacs.9b02198
日期:2019.4.24
method for the stereoselective synthesis of highly functionalized oxygen heterocycles using allyl or benzyl alcohols as alkylating agents is presented. The process is efficient and atom economic, generating water as the only stoichiometric byproduct. Substoichiometric amounts of Ti(OiPr)4 in HFIP solvent are key to this reactivity, and the method tolerates a broad substitution pattern on both the alcohol
Stereoselective aziridination of cyclic allylic alcohols using chloramine-T
作者:Susannah C. Coote、Peter O'Brien、Adrian C. Whitwood
DOI:10.1039/b811137e
日期:——
TsNClNa and t-BuSO(2)NClNa, BusNClNa) has been explored. The stereoselectivity of these reactions was highly dependent on the structure of the allylic alcohol and the chloramine salt. Generally, mixtures of cis- and trans-hydroxy aziridines were obtained, in which the major diastereomer was the cis-hydroxy aziridine, whilst complete cis-diastereoselectivity was observed in the aziridination of 1,3-disubstituted