21429-06-1Relevant articles and documents
Switching with orthogonal stimuli: Electrochemical ring-closure and photochemical ring-opening of bis(thiazolyl)maleimides
Herder, Martin,Utecht, Manuel,Manicke, Nicole,Grubert, Lutz,Paetzel, Michael,Saalfrank, Peter,Hecht, Stefan
, p. 1028 - 1040 (2013)
The photochemistry as well as electrochemistry of novel donor-acceptor bis(morpholinothiazolyl)-maleimides has been investigated. Proper substitution of these diarylethene-type molecular switches leads to the unique situation in which their ring-closure can only be accomplished electrochemically, while ring-opening can only be achieved photochemically. Hence, these switches operate with orthogonal stimuli, i.e. redox potential and light, respectively. The switch system could be optimized by introducing trifluoromethyl groups at the reactive carbon atoms in order to avoid by-product formation during oxidative ring closure. Both photochemical and electrochemical pathways were investigated for methylated, trifluoromethylated, and nonsymmetrical bis(morpholinothiazolyl) maleimides as well as the bis(morpholinothiazolyl)cyclopentene reference compound. With the aid of the nonsymmetrical mixed derivative, the mechanism of electrochemically driven ring closure could be elucidated and seems to proceed via a dicationic intermediate generated by two-fold oxidation. All experimental work has been complemented by density functional theory that provides detailed insights into the thermodynamics of the ring-open and closed forms, the nature of their excited states, and the reactivity of their neutral as well as ionized species in different electronic configurations. The particular diarylethene systems described herein could serve in multifunctional (logic) devices operated by different stimuli (inputs) and may pave the way to converting light into electrical energy via photoinduced pumping of redox-active meta-stable states.
Copper- and Cobalt-Catalyzed Syntheses of Thiophene-Based Tertiary Amines
Bouarfa, Salima,Gra?l, Simon,Ivanova, Maria,Langlais, Timothy,Bentabed-Ababsa, Ghenia,Lassagne, Frédéric,Erb, William,Roisnel, Thierry,Dorcet, Vincent,Knochel, Paul,Mongin, Florence
, p. 3244 - 3258 (2019/06/08)
Thienylzinc halides and related compounds prepared by deprotonation followed by transmetalation were used in copper-catalyzed amination using N-benzoyloxy secondary amines. By extending the reaction to 1,5-naphthyridine, it was showed that the competitive dimer formation observed in the case of thiophenes was linked with the low stability of some thienylamines rather than homocoupling. Interestingly, thienylzinc halides and related compounds prepared by transmetalation of thienylmagnesium halides, either prepared from their bromo-precursors or generated by deprotometalation, were satisfactorily employed in cobalt-catalyzed aminations. Finally, aminothiophenes were involved in copper-catalyzed mono- and di-N-arylations, affording differently substituted di- and triphenylamines.
Copper-catalyzed electrophilic amination of heteroarenes and arenes by C-H zincation
McDonald, Stacey L.,Hendrick, Charles E.,Wang, Qiu
supporting information, p. 4667 - 4670 (2014/05/20)
Direct amination of heteroarenes and arenes has been achieved in a one-pot C-H zincation/copper-catalyzed electrophilic amination procedure. This amination method provides an efficient and rapid approach to access a diverse range of heteroaromatic and aromatic amines including those previously inaccessible using C-H amination methods. The mild reaction conditions and good functional-group compatibility demonstrate its great potential for the synthesis of important and complex amines. Direct amination of heteroarenes and arenes has been achieved in a one-pot zincation/Cu(OAc)2-catalyzed amination sequence using O-acylhydroxylamines. The method provides a rapid and efficient approach to a range of aromatic and heteroaromatic amines, including those which were previously inaccessible by using C-H amination methods. tmp=2,2,6,6- tetramethylpiperidide.
