Multichannel Reaction of α‐Bromo­enones with 1,2‐Diamines: Synthesis of 1,4‐Diazabicyclo[4.1.0]hept‐4‐enes by Reaction with N‐Unsubstituted 1,2‐Diamines

Abstract

The reaction of 2‐bromoenones with N‐unsubstituted 1,2‐diamines was studied. An easy access to 1,4‐diazabicyclo[4.1.0]hept‐4‐enes was developed. The multistep mechanism of the reaction is discussed. Final conclusions on the influence of the structure of the starting 2‐bromoenones and 1,2‐diamines on the direction of the reaction are established.

Assembly of Trifluoromethylated Morpholines through Cascade Reactions of Bromoenones with Secondary Amino Alcohols

“…It is very important that the reaction of ketones 1 with amino alcohols 2 is highly stereoselective: in the NMR spectra of the products 3 and 5 there is only one set of signals. Previously, we have observed the same high stereoselectivity in the formation of piperazines from diamines and bromoenones 1 , , …”

“…We have also shown that the unusual 1,2‐migration of the trifluoromethyl group completed a cascade of transformations of CF 3 ‐bromoenones with symmetrically substituted ethylenediamines leading to a very rare type of piperazine derivatives . The reaction of the same bromoenones with N , N′ ‐unsubstituted 1,2‐diamines selectively gave 3,6‐diaza‐bicyclo[4.1.0]hept‐2‐enes . Finally, fluorinated α‐bromoenones react smoothly with β‐mercapto alcohols to give 1,4‐oxathianes in moderate yields; amino alcohols containing a primary amino group give morpholines and/or 1,4‐oxazepanes ― a previously unknown heterocyclic system ― in good to excellent yields and often with very high stereoselectivity .…”

The Wonderful Chemistry of Trifluoromethyl α‐Haloalkenyl Ketones

“…Diamines bearing two primary amino groups react with bromoenones in other ways. In all cases these reactions represent extremely short routes to mono‐ or bis‐aziridine derivatives, (Scheme ).…”

One‐Pot, Atom and Step Economy (PASE) Assembly of Trifluoromethylated Pyrimidines from CF3‐Ynones

“…The most efficient approach, however, for the construction of such heterocyclic systems employs fluorinated building blocks. For example, we have recently demonstrated that fluorinated bromoenones can be used for the assembly of trifluoromethylated piperazinones, bicyclic piperazines, morpholines, oxazepanes, and other heterocycles …”