Reactivity of a Pd(II) carbene towards 2,6-dimesitylphenyldiazomethane and 2,6-dimesitylphenylazide

Group-Transfer Reactions of a Cationic Iridium Alkoxycarbene Generated by Ether Dehydrogenation

“…As complexes of square planar d 8 metal ions, 3 and 4 bear a filled high-lying d z 2 orbital which has been implicated in so-called Roper-type carbene chemistry of which group-transfer reactions of azides represent one example. ,,, Other electrophiles including CO 2 , carbonyl sulfide, and phenyl isocyanate have been demonstrated to give formate esters, thioformates, and formimidates, respectively. , We suspected that other substrates might undergo similar group-transfer reactions via what has been proposed as an initial [2 + 2] cycloaddition to alkoxycarbene 3 and identified diazoalkanes, ketenes, and alkyl nitrites as possible candidates for CC or CO bond-forming chemistry. Just as alkyl azides are observed to transfer a formal nitrene equivalent, we hypothesized that diazoalkanes and alkyl aryl ketenes − might serve as carbene equivalents to give the products of formal carbene–carbene cross-coupling.…”

Group 11 complexes of a bulky triazene ligand

“…The deuterated solvent was used as an internal reference for 13 C{ 1 H} NMR spectra. α,α,α-Trifluoro toluene was used as an external standard for 19 F NMR. C 6 D 6 (99.5%) and CD 2 Cl 2 (99.8%) were purchased from Cambridge Isotope Laboratories Inc. and stored over activated molecular sieves for 2 days prior to use.…”

“…7,8 Typically, bulky groups have been applied in triazene synthesis including aryl [9][10][11][12][13] or redox active ferrocenyl groups, 14,15 coupled with the NHC, [16][17][18] but for π-conjugated triazenes, a combination of both has been less frequently explored. 19,20 Generally, cyclic and linear triazene ligands are derived from N,N′-di-substituted precursors which become anionic ligands once deprotonated and coordinated to metals. The combi-nation of an N-aryl group with an NHC enables the formation of a neutral triazene ligand with (E)-and (Z)-isomers as neutral and zwitterionic respectively (Fig.…”

“…1D) has been observed upon reacting a diaryl carbene Pd(II) complex with the bulky TerMesN 3 , however, the imido-nature of the insertion product acting as a CvN π-donor ligand is a rare example of a π-conjugated triazene without the use of an NHC. 19 The work presented herein focuses on preparing a sterically bulky neutral π-conjugated triazene ligand, employing the bulky 2,6-bis(2,4,6-trimethylphenyl)phenyl (TerMes) along with the bulky N-heterocyclic carbene (NHC), N,N′-2,6-bis (diisopropylphenyl)-3,4-dihydroimidazol-2-ylidene (SIPr) on either side of the triazene N 3 core to give 1 (Fig. 3).…”

“…1D) has been observed upon reacting a diaryl carbene Pd( ii ) complex with the bulky TerMesN 3 , however, the imido-nature of the insertion product acting as a CN π-donor ligand is a rare example of a π-conjugated triazene without the use of an NHC. 19…”