Synthesis of 2-aryl-4-chloropyrroles via ring expansion of 2-aryl-1-chlorocyclopropanecarbaldehydes

β,β,β‐Trichloroethyl‐NH‐Enamine as Viable System for 5‐Endo‐trig Radical Cyclization via Multifaceted CuI−CuII Redox Catalysis: Single Step Synthesis of Multi‐Functionalized NH‐Pyrroles

“…Advantageously, this Cu(I)/PMDETA‐catalyst uses overall lesser amount of PMDETA and lesser reaction time (Table , entry ‐ 5 ) than required for the aromatization of an isolated halogenated pyrrolidine in the next aromatization reaction. Thus, it shortens the synthetic operations and reaction time for, otherwise a multi‐step synthetic protocol …”

“…The double dehydrohalogenations‐isomerization of these heterocycles to corresponding aromatic compounds require an excess amount of strong base (DBU 2.5 eq.) and longer reaction time (24 hrs) in the next step of the synthesis protocols –. Advantageously, this Cu(I)/PMDETA‐catalyst uses overall lesser amount of PMDETA and lesser reaction time (Table , entry ‐ 5 ) than required for the aromatization of an isolated halogenated pyrrolidine in the next aromatization reaction.…”

Flexible synthesis of polyfunctionalised 3-fluoropyrroles

“…14,15 Mechanistically, we believe that this aromatisation process takes place through hemiaminal formation followed by elimination of water and double bond isomerisation. 15,16 The alkylation-aromatisation methodology was then expanded by including an array of nucleophiles as to allow for the selective introduction of substituents at the C2 position of the C3 fluorinated-pyrrole ring. Thus, a collection of organometallic reagents including DIBAL-H, n-butyllithium, phenyllithium and allylmagnesium bromide were used to generate the desired substituted pyrroles 10-13 in high yields ( Table 1).…”

“…Thus, a collection of organometallic reagents including DIBAL-H, n-butyllithium, phenyllithium and allylmagnesium bromide were used to generate the desired substituted pyrroles 10-13 in high yields ( Table 1). [14][15][16] Having demonstrated the ability to incorporate substituents at the pyrrole C2 position through an alkylation-aromatisation process, it was decided to explore the ability of our methodology to incorporate substituents in the other pyrrole positions.…”

Stereospecific Syntheses of Enaminonitriles and β-Enaminoesters via Domino Ring-Opening Cyclization (DROC) of Activated Cyclopropanes with Pronucleophilic Malononitriles

“…In recent years, donor–acceptor (DA) cyclopropanes have become one of the important classes of building blocks and the related chemistry has made significant contributions to organic synthesis . Synthetic exploration of DA cyclopropanes by utilizing their inherent proclivity to undergo a wide range of ring-opening transformations with functionalized nucleophiles has led to the development of interesting routes to various carbo- and heterocyclic compounds. For over a decade and a half, we have been exploring and utilizing a wide variety of S N 2-type ring-opening transformations of activated small ring aza-hetero- and carbacycles to conveniently access a number of heterocyclic and carbocyclic compounds, , respectively, of contemporary interest.…”