1,2-Amino Alcohols and Their Heterocyclic Derivatives as Chiral Auxiliaries in Asymmetric Synthesis

Recent developments in the stereoselective synthesis of α-aminoacids

Stereoselective Addition to N-Activated Pyridines James A. Bull,‡ James J. Mousseau, Guillaume Pelletier,† and Andre ́ B. Charette*,† †Department of Chemistry, Universite ́ de Montreál, P.O. Box 6128, Station Downtown, Montreál, Queb́ec, Canada H3C 3J7 ‡Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, U.K. Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA

Synthesis of Pyridine and Dihydropyridine Derivatives by Regio- and Stereoselective Addition to N-Activated Pyridines

2.1.5. Electrophilic Attack on CdC 3994 2.1.6. NH Insertions in Diazo Compounds 3994 2.1.7. Pd Catalyzed Cyclizations 3994 2.2. Cyclizations by C-C Bond formation 3995 2.2.1. Nucleophilic Displacement of Halides 3995 2.2.2. Cyclizations Involving CdO Group 3995 2.3. Cycloadditions 3996 2.4. Ring Rearrangements 3997 2.4.1. Rearrangements of Four-Membered Rings 3997 2.4.2. Rearrangements of Larger Rings 3998 2.5. Reduction of Azetidin-2-ones 3998 2.6. Miscellaneous Syntheses 3999 2.7. Important Classes of Compounds 4000 2.7.1. Natural Products 4000 2.7.2. Azetidine Carboxylic Acids 4001 2.7.3. Exomethylene Azetidines 4002 2.7.4. Ligands for Metal-Catalyzed Reactions and Chiral Auxiliaries 4003

Novel syntheses of azetidines and azetidinones.

Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

Chiral oxazolidinones from N-Boc derivatives of β-amino alcohols. Effect of a N-methyl substituent on reactivity and stereoselectivity

Synthesis of cytotoxic ferrocenyl flavones via a ferricenium-mediated 1,6-oxidative cyclization

Treatment of α-alkenyl N-Boc oxazolidines with N-bromosuccinimide leads to epoxy oxazolidines via a bromocyclocarbamation reaction which is completely stereoselective. Action of sodium azide on these epoxides, followed by a few functional group manipulations, eventually affords chiral β-amino alcohols which are intermediates for the enantioselective synthesis of bioactive products:  the anti side chain of taxol and a hydroxyethylamine isostere. Both the bromocarbamation cyclization and the nucleophilic cleavage of epoxides are totally regioselective. AM1 calculations suggest that this selectivity is controlled by the positive charge distribution at the electrophilic centers.

Regio- and Stereocontrolled Formation of Chiral Epoxy Oxazolidines via Bromocarbamation of N-Boc Alkenyl Oxazolidines. Application to Asymmetric Synthesis.

Radical cyclizations of 1,4-dihydropyridines. Synthesis of chiral fused nitrogen heterocycles. Synthesis of lupinine and epilupinine

Highly Stereoselective trans Addition of π‐Type Nucleophiles to a Bicyclic N‐Acyliminium Ion – Application to the Synthesis of Indolizidine and Pyrrolizidine Alkaloids

Louis Hamon

Papers

Chiral oxazolidinones from N-Boc derivatives of β-amino alcohols. Effect of a N-methyl substituent on reactivity and stereoselectivity

Synthesis of cytotoxic ferrocenyl flavones via a ferricenium-mediated 1,6-oxidative cyclization

Regio- and Stereocontrolled Formation of Chiral Epoxy Oxazolidines via Bromocarbamation of N-Boc Alkenyl Oxazolidines. Application to Asymmetric Synthesis.

Radical cyclizations of 1,4-dihydropyridines. Synthesis of chiral fused nitrogen heterocycles. Synthesis of lupinine and epilupinine

Highly Stereoselective trans Addition of π‐Type Nucleophiles to a Bicyclic N‐Acyliminium Ion – Application to the Synthesis of Indolizidine and Pyrrolizidine Alkaloids