Asymmetric synthesis of heterocyclic chloroamines and aziridines by enantioselective protonation of catalytically generated enamines

We report a method for the synthesis of chiral vicinal chlo-roamines via asymmetric protonation of catalytically gener-ated prochiral chloroenamines using chiral Brønsted acids. The process is highly enantioselective, with the origin of asymmetry and catalyst substituent effects elucidated by DFT calculations. We show the utility of the method as an approach to the synthesis of a broad range of heterocycle-substituted aziridines by treatment of the chloroamines with base in a one-pot process, as well as the utility of the process to allow access to vicinal diamines.

Catalytic, Enantioselective Diamination of Alkenes

Enantioselective diamination of alkenes represents one of the most straightforward methods to access enantioenriched, vicinal diamines, which are not only frequently encountered in biologically active compounds, but also have broad applications in asymmetric synthesis. Although the analogous dihydroxylation of olefins is well-established, the development of enantioselective olefin diamination lags far behind. Nevertheless, several successful methods have been developed that operate by different reaction mechanisms, including a cycloaddition pathway, a two-electron redox pathway, and a radical pathway. This short review summarizes recent advances and identifies limitations, with the aim of inspiring further developments in this area.1 Introduction2 Cycloaddition Pathway3 Two-Electron Redox Pathway3.1 Pd(0)/Pd(II) Diamination3.2 Pd(II)/Pd(IV) Diamination3.3 I(I)/I(III) Diamination3.4 Se(II)/Se(IV) Diamination4 One-Electron Radical Pathway4.1 Cu-Catalyzed Diamination4.2 Fe-Catalyzed Diamination5 Summary and Outlook

Highly diastereoselective synthesis of vicinal diamines via Rh-catalyzed three-component reaction of diazo compounds with diarylmethanimines and ketimines

A Rh-catalyzed diastereoselective three-component reaction of diazo compounds with diarylmethanimines and ketimines has been reported, which offers an efficient and convenient access to furnish vicinal diamine derivatives with two tertiary...

Direct Synthesis of Unprotected 2-Azidoamines from Alkenes via an Iron-Catalyzed Difunctionalization Reaction

<div> <p>Unprotected, primary 2-azidoamines are versatile precursors to vicinal diamines, which are among the most common motifs in biologically active compounds. Herein, we report their operationally simple synthesis through an iron-catalyzed difunctionalization of alkenes. A wide array of alkene substrates are tolerated, including complex drug-like molecules and a tripeptide. Facile derivatizations of the azidoamine group demonstrate the versatility of this masked diamine motif in chemoselective, orthogonal transformations. Applications of the methodology in the concise synthesis of RO 20-1724 and in a formal total synthesis of (±)-hamacanthin B further demonstrate the broad synthetic potential of this highly functional group tolerant reaction.</p> </div>

Direct Synthesis of Unprotected 2-Azidoamines from Alkenes via an Iron-Catalyzed Difunctionalization Reaction

<div> <p>Unprotected, primary 2-azidoamines are versatile precursors to vicinal diamines, which are among the most common motifs in biologically active compounds. Herein, we report their operationally simple synthesis through an iron-catalyzed difunctionalization of alkenes. A wide array of alkene substrates are tolerated, including complex drug-like molecules and a tripeptide. Facile derivatizations of the azidoamine group demonstrate the versatility of this masked diamine motif in chemoselective, orthogonal transformations. Applications of the methodology in the concise synthesis of RO 20-1724 and in a formal total synthesis of (±)-hamacanthin B further demonstrate the broad synthetic potential of this highly functional group tolerant reaction.</p> </div>