Bridged N-Heterocyclic/Mesoionic (NHC/MIC) Heterodicarbenes as Ligands for Transition Metal Complexes.
Following a copper catalyzed alkyne azide cycloaddition (CuAAC) and N-alkylation protocols, we report the preparation of a hybrid N-heterocyclic/mesoionic [NHC(H+)-MIC(H+)][2I]2-salt (1) in high yields. The treatment of salt 1 with Cu2O and KI yields a second hybrid NHC/MIC proligand featuring a tetraiodocuprate anion [NHC(H+)-MIC(H+)][Cu2I4]2-(2). Through selective deprotonation and metalation, both salts 1 and 2 can generate either the chelate heterodicarbene complexes (3) with the rare [NHC·(M)·MIC]+[MX2]-general formula (M = PdII, RhI) or NHC-anchored/pendent triazolium species (4) [NHC·(M)-MIC(H+)]. If the triazolium moiety of type 4 complexes is deprotonated with KHMDS in the presence of a second metal center, a series of heterobimetallic complexes of the type [NHC·(M)-MIC·(M')] (5) are achieved. Interestingly, the reaction of salt 2 with KHMDS yields the bimetallic copper heterodicarbene (6) which can be a useful transfer reagent for the preparation of type 3 complexes. A variety of synthetic routes for the preparation of complexes 3-5 and their full characterization in solution and in the solid state will be discussed.
Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana-Azcapotzalco , Avenida San Pablo No. 180, Ciudad de México 02200, México.|CONACYT, Área Académica de Química, Universidad Autónoma del Estado de Hidalgo , Carretera Pachuca-Tulancingo Km. 4.5, Mineral de la Reforma, Hidalgo 42090, México.
Daniel
http://orcid.org/0000-0001-9170-588X
D
Mendoza-Espinosa
Área Académica de Química, Universidad Autónoma del Estado de Hidalgo , Carretera Pachuca-Tulancingo Km. 4.5, Mineral de la Reforma, Hidalgo 42090, México.
Alejandro
A
Alvarez-Hernández
Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana-Azcapotzalco , Avenida San Pablo No. 180, Ciudad de México 02200, México.
Deyanira
D
Angeles-Beltrán
Departamento de Ciencias Básicas, Universidad Autónoma Metropolitana-Azcapotzalco , Avenida San Pablo No. 180, Ciudad de México 02200, México.
Guillermo E
GE
Negrón-Silva
Área Académica de Química, Universidad Autónoma del Estado de Hidalgo , Carretera Pachuca-Tulancingo Km. 4.5, Mineral de la Reforma, Hidalgo 42090, México.
Oscar R
OR
Suárez-Castillo
CONACYT, Área Académica de Química, Universidad Autónoma del Estado de Hidalgo , Carretera Pachuca-Tulancingo Km. 4.5, Mineral de la Reforma, Hidalgo 42090, México.
José M
JM
Vásquez-Pérez