2 research outputs found
One-pot three-component tandem reaction: Synthesis of aryl/alkyl cyanamides libraries and their further conversion into tetrazole derivatives
<p>We have developed methodology for the synthesis of aryl/alkyl cyanamides from amines in one-pot four steps reaction using cheap, readily available and air stable copper source as catalyst under mild reaction conditions. We have also studied the application of cyanamides. In this connection, we could construct aryl tetrazolamine from cyanamides using click reaction</p
Phenanthridine-Containing Pincer-like Amido Complexes of Nickel, Palladium, and Platinum
Proligands based
on bisÂ(8-quinolinyl)Âamine (<b>L1</b>) were prepared containing
one (<b>L2</b>) and two (<b>L3</b>) benzo-fused N-heterocyclic
phenanthridinyl (3,4-benzoquinolinyl) units. Taken as a series, <b>L1</b>–<b>L3</b> provides a ligand template for exploring
systematic π-extension in the context of tridentate pincer-like
amido complexes of group 10 metals (<b>1-M</b>, <b>2-M</b>, and <b>3-M</b>; <b>M</b> = Ni, Pd, Pt). Inclusion of
phenanthridinyl units was enabled by development of a cross-coupling/condensation
route to 6-unsubstituted, 4-substituted phenanthridines (<b>4-Br</b>, <b>4-NO</b><sub><b>2</b></sub>, <b>4-NH</b><sub><b>2</b></sub>) suitable for elaboration into the target ligand
frameworks. Complexes <b>1-M</b>, <b>2-M</b>, and <b>3-M</b> are redox-active; electrochemistry and UV–vis absorption
spectroscopy were used to investigate the impact of π-extension
on the electronic properties of the metal complexes. Unlike what is
typically observed for benzannulated ligand–metal complexes,
extending the π-system in metal complexes <b>1-M</b> to <b>2-M</b> to <b>3-M</b> led to only a moderate red shift in
the relative highest occupied molecular orbital (HOMO)–lowest
unoccupied molecular orbital (LUMO) gap as estimated by electrochemistry
and similarly subtle changes to the onset of the lowest-energy absorption
observed by UV–vis spectroscopy. Time-dependent density functional
theory calculations revealed that benzannulation significantly impacts
the atomic contributions to the LUMO and LUMO+1 orbitals, altering
the orbital contributions to the lowest-energy transition but leaving
the energy of this transition essentially unchanged