Stereoselective Transformations of meso Bicyclic Hydrazines: Versatile Access to Functionalized Aminocyclopentanes

Abstract

Bicyclic hydrazines, prepared by cycloaddition of cyclopentadiene and diazo compounds, have great synthetic potential. Numerous asymmetric transformations of these building blocks have been developed, involving the electrophilicity of their strained double bond, ring-opening reactions or skeletal rearrangements. All these transformations are fully diastereoselective, and, in some cases, enantioselective, enabling the preparation of a wide range of useful synthetic intermediates from a single precursor in a few synthetic steps.

Copper-Catalyzed Enantioselective and Exo-Selective Addition of Silicon Nucleophiles to 7-Oxa- and 7-Azabenzonorbornadiene Derivatives

“…In fact, there are hardly any additional examples beyond those mentioned above. , Given the now broad applicability of copper-catalyzed enantioselective silylation reactions , with Si–B reagents 7 as silicon pronucleophiles, e.g., their addition to cyclopropenes [ 6 → 8 (Scheme , top)], we set out to tackle the formal hydrosilylation of benzonorbornadiene congeners (Scheme , bottom). In this Letter, we report the highly enantioselective and exo -selective silylation of 7-oxa- and 7-azabenzonorbornadiene derivatives , with no ring opening. , …”

Diastereoselective Ring Homologation of Bicyclic Hydrazines: Access to cis-1,3-Diaminocyclohexitols

“… Furthermore, substituted cis -1,3-diaminocycloalkanes have been reported to be valuable fragments or scaffolds for the design of RNA binders . In this context, our group has been involved in the synthesis of polysubstituted 1,3-diamino cyclopentanes 3 or piperidines 4 starting from bicyclic hydrazine 5 . Herein, we wish to report a straightforward and fully stereoselective approach toward hydroxylated 1,3-di- and 1,3,5-triaminocyclohexanes from a single precursor.…”

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

“…Heterobicyclic alkenes undergo important chemical transformations to provide highly substituted cyclic and acyclic systems [1–2]. Oxabicyclic alkene 1 specifically can undergo a variety of chemical transformations to generate highly substituted and complex organic frameworks (Scheme 1) [3–13].…”