A novel DABCO-catalyzed Ireland-Claisen [3,3]-rearrangement of allylic acrylates to give a-methylene-γ,δ -unsaturated carboxylic acids in the presence of an excess of TMSCl and DBU in refluxing acetonitrile was developed. The protocol provides an easy entry to a-methylene-γ,δ-unsaturated carboxylic acids from allylic alcohols in good yields.
Enantio- and Stereospecific Syntheses of 15(<i>R</i>)-Me-PGD<sub>2</sub>, A Potent and Selective DP<sub>2</sub>−Receptor Agonist
作者:Pranav Patel、Gue-Jae Lee、Seongjin Kim、Gail E. Grant、William S. Powell、Joshua Rokach
DOI:10.1021/jo801190m
日期:2008.9.19
The first total synthesis of 15(R)-Me-PGD2 3 is reported. The synthesis is based on the enantioselective and stereospecific syntheses of synthon 17 and its attachment to the five-membered ring by a olefin cross metathesis reaction. This approach permits the introduction of a side chain with a predetermined stereogenic center into the prostanoid ring, resulting in the synthesis of 15R-methyl prostaglandin
Prenyl Praxis: A Method for Direct Photocatalytic Defluoroprenylation
作者:Sonal Priya、Jimmie D. Weaver
DOI:10.1021/jacs.8b09156
日期:2018.11.28
method that provides access to "hybrid molecules" that possess both the functionality of a prenyl group and fluorinated arenes. This approach involves direct prenyl group transfer under very mild conditions, displays excellent functional group tolerance, and includes relatively short reaction times (<4 h), which is the fastest photocatalytic C-F functionalization developed to date. Additionally, the
methods for oxidative rearrangement of tertiary allylic alcohols to β-substituted α,β-unsaturated carbonyl compounds employing oxoammonium salts are described. The methods developed are applicable to acyclic substrates as well as medium membered ring substrates and macrocyclic substrates. The counteranion of the oxoammonium salt plays crucial roles on this oxidative rearrangement.
Regioselective and Stereospecific Rhodium-Catalyzed Allylic Cyanomethylation with an Acetonitrile Equivalent: Construction of Acyclic β-Quaternary Stereogenic Nitriles
作者:Mai-Jan Tom、P. Andrew Evans
DOI:10.1021/jacs.0c02316
日期:2020.7.15
A highlyregioselective and stereospecific rhodium-catalyzed cyanomethylation of tertiary allyliccarbonates for the construction of acyclic β-quaternary stereogenic nitriles is described. This protocol represents the first example of a metal-catalyzed allylicsubstitution reaction using a triorganosilyl-stabilized acetonitrile anion, which permits access to several carbonyl derivatives that are challenging