Stereoselective Transformationsof meso Bicyclic Hydrazines: VersatileAccess to Functionalized Aminocyclopentanes

Bicyclic hydrazines, prepared by cycloaddition of cyclopentadieneand diazo compounds, have great synthetic potential. Numerous asymmetrictransformations of these building blocks have been developed, involvingthe electrophilicity of their strained double bond, ring-openingreactions or skeletal rearrangements. All these transformationsare fully diastereoselective, and, in some cases-, enantioselective,enabling the preparation of a wide range of useful synthetic intermediatesfrom a single precursor in a few synthetic steps. 1 Introduction 2 Preparation and Conformational Properties of Bicyclic [nl]Hydrazines 3 Synthetic Transformations without Ring Fragmentation 3.1 Hydroboration 3.2 Hydroformylation and Halocarbomethoxylation 3.3 Dihydroxylation and Aminohydroxylation 3.4 Hydroarylation 3.5 Sequential Arylation-Alkynylation 3.6 Arylative Cyclization 3.7 Cyclopropanation 3.8 Pauson-Khand Reaction 3.9 Cycloaddition Reactions 4 Synthetic Transformations with Ring Fragmentation 4.1 Palladium-Catalyzed Ring-Opening Reactions 4.2 Copper-Catalyzed Ring-Opening Reactions 4.3 Rhodium-Catalyzed Ring-Opening Reactions 4.4 Ruthenium-Catalyzed Ring-Opening-Metathesis Reactions andOxidative Cleavage 5 Rearrangements 5.1 Rearrangements Involving Allylic Cations 5.2 Rearrangements Involving Aziridiniums 6 Synthetic Applications 7 Conclusion