Abstract
This review highlights the advances in the literature up to July
2008 on the intermolecular reactions of acyclic and cyclic N -acyliminium ions. This is an update
of an earlier review in 2000 on this topic and does not include
intramolecular addition reactions to N -acyliminium
ions which was recently reviewed. This review is presented in two
parts, with the first part dealing with acyclic and pyrrolidinone-based N -acyliminium ions. Part II continues
with other five-membered heterocyclic derivatives and higher systems.
Part I
1 Introduction
2 Acyclic N -Acyliminium Ions
2.1 Synthesis of Acyclic N -Acyliminium
Ion Precursors
2.2 Reactions of Acyclic N -Acyliminium
Ions
2.2.1 Reactions with Nucleophiles
2.2.1.1 Silicon-Based Nucleophiles
2.2.1.2 Aromatic Nucleophiles
2.2.1.3 Organostannanes
2.2.1.4 Organometallic Reagents
2.2.1.5 Thiols
2.2.1.6 Alkenes
2.2.1.7 Nitrogen Nucleophiles
2.2.1.8 Alkyl Radicals
2.2.2 Cycloaddition Reactions
2.2.3 Cationic Carbohydroxylation Reactions
3 Cyclic N -Acyliminium Ions
3.1 Synthesis of Cyclic N -Acyliminium
Ion Precursors
3.1.1 Preparation of Iminium Ions in situ by Anodic Oxidation
3.2 Five-Membered-Ring N -Acyliminium
Ions
3.2.1 Reactions of Pyrrolidinone-Based N -Acyliminium
Ions
3.2.1.1 Silicon-Based Nucleophiles
3.2.1.2 Aromatic Nucleophiles
3.2.1.3 Organostannanes
3.2.1.4 Organometallic Reagents
3.2.1.5 Active Methylene Compounds
3.2.1.6 Nitrile Nucleophiles (Ritter Reaction)
Part II
3.2.2 Reactions of N -Acylpyrrolidine-Based N -Acyliminium Ions with Nucleophiles
3.2.3 Reactions of Oxazolidinone-Based N -Acyliminium
Ions with Nucleophiles
3.2.4 Cyclocondensation Reaction of N -Aminidinyl
Iminium Ions
3.3 Reactions of Six-Membered-Ring N -Acyliminium
Ions
3.3.1 Reactions of Piperidinone-Based N -Acyliminium
Ions with Nucleophiles
3.3.3 Reactions of Piperazine-Based N -Acyliminium
Ions with Nucleophiles
3.3.4 Reactions of Pyridine-Based N -Acyliminium
Ions with Nucleophiles
3.3.5 Reactions of N ,O -Acetal Oxathiazinane N -Sulfonyliminium
Ions with Nucleophiles
3.4 Reactions of Seven-Membered-Ring N -Acyliminium
Ions
3.4.1 Reactions with Silicon-Based Nucleophiles
3.4.2 Cycloaddition Reactions
3.5 Reactions of Bicyclic N -Acyliminium
Ions
3.5.1 Reactions with Nucleophiles
3.5.2 Cycloaddition Reactions
3.6 Other Systems
3.6.1 Silicon-Based Nucleophiles
4 Stereochemical Outcomes
5 Conclusions
Key words
N -acyliminium ion - nucleophilic
addition - cycloaddition - aromatic electrophilic
substitution - radical addition - peptides - pyrrolidines - piperidines
