Palladium-Catalyzed Allylic Substitution at Four-Membered-Ring Systems: Formation of η1-Allyl Complexes and Electrocyclic Ring Opening

2013 ◽  
Vol 52 (24) ◽  
pp. 6313-6316 ◽  
Author(s):  
Davide Audisio ◽  
Gopinadhanpillai Gopakumar ◽  
Lan-Gui Xie ◽  
Luís G. Alves ◽  
Cornelia Wirtz ◽  
...  
Keyword(s):  
Ring Opening ◽  
Membered Ring ◽  
Allylic Substitution ◽  
Ring Systems ◽  
Palladium Catalyzed

Norbornene in Organic Synthesis

Synthesis ◽  
2018 ◽  
Vol 50 (15) ◽  
pp. 2799-2823 ◽  
Author(s):  
Jianhui Huang ◽  
Caifeng Li ◽  
Liu Liu ◽  
Xuegang Fu
Keyword(s):  
Ring Opening ◽  
Membered Ring ◽  
Ring Formation ◽  
Oxidation Reactions ◽  
Organic Transformations ◽  
Substitution Reactions ◽  
Reaction Conditions ◽  
Multistep Synthesis ◽  
Palladium Catalyzed

The norbornene skeleton possesses an alkene functionality with a fixed conformation, and represents unique reactivity. The use of norbornene and analogues as substrates is overviewed; reactivities are discussed as well as the role of norbornenes as ligands assisting modern organic transformations.1 Introduction2 Synthesis of Substituted Norbornenes2.1 Preparation of Functionalized Norbornenes by Deprotonation and Substitution Reactions2.2 Preparation of Functionalized Norbornenes under Palladium-Catalyzed­ Reaction Conditions2.3 Alkylation of Norbornene2.4 Multistep Synthesis3 Synthesis of Substituted Norbornanes3.1 Three-Membered-Ring Formation3.2 Formation of Four-Membered Rings3.3 Five- and Six-Membered Ring Formation3.4 Syntheses of Difunctionalized Norbornanes4 Synthesis of Cyclopentanes4.1 Oxidation Reactions4.2 Ring-Opening Cross Metathesis (ROCM)4.3 Ring-Opening Metathesis Polymerization (ROMP)4.4 Palladium-Catalyzed Ring-Opening of Norbornene5 Norbornene-Mediated Reactions5.1 Palladium Insertion into Carbon–Halide Bonds5.2 Palladium Insertion into N–H and C–H Bonds5.3 Norbornene as Ligand in Mediated Reactions6 Conclusion

Palladium-Catalyzed Asymmetric Allylic Substitution Using Phosphoramidite Ligands Bearing 1,1-Binaphthyl Skeleton

2008 ◽  
Vol 5 (5) ◽  
pp. 346-348 ◽  
Author(s):  
Yongguang Gao ◽  
Xinsheng Li ◽  
Weiyi Chen ◽  
Dongcheng Xu
Keyword(s):  
Allylic Substitution ◽  
Palladium Catalyzed

ChemInform Abstract: Five-Membered Ring Systems: Thiophenes and Se/Te Analogues

ChemInform ◽  
2009 ◽  
Vol 40 (23) ◽  
Author(s):  
Tomasz Janosik ◽  
Jan Bergman
Keyword(s):  
Membered Ring ◽  
Ring Systems

ChemInform Abstract: Three-Membered Ring Systems

ChemInform ◽  
2010 ◽  
Vol 24 (51) ◽  
pp. no-no
Author(s):  
A. PADWA ◽  
S. S. MURPHREE
Keyword(s):  
Membered Ring ◽  
Ring Systems

Delineating the possibilities for intramolecular interception of the squarate ester cascade through the use of metalated enecarbamates

2000 ◽  
Vol 78 (6) ◽  
pp. 689-696 ◽  
Author(s):  
Jinsung Tae ◽  
Leo A Paquette
Keyword(s):  
Ring Opening ◽  
Membered Ring ◽  
Sequential Treatment ◽  
Nucleophilic Attack ◽  
Ring Strain ◽  
Multistep Process

Highly functionalized and annulated 2,4-cyclooctadienones are formed in a stereoselective manner by sequential treatment of squarate esters with a lithiated enecarbamate (six-membered ring or larger) and a cycloalkenyl- or 1-alkenyllithium reagent. The mechanistic details of this multistep process are presented. Particular attention is drawn to the step that involves intramolecular nucleophilic attack by a proximal oxido anion at the carbamate carbonyl and results in redirection of the cascade. This step is thwarted when five-membered cyclic enecarbamates are employed because of the excessive buildup of ring strain in the associated transition state.Key words: squarate esters, enecarbamates, conrotatory ring opening, intramolecular acylation, alkenyllithium reagents.

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