Grafting Ti(=NtBu)(Me Pyr) (py) (Me Pyr= 2,5-dimethylpyrrolyl, py=pyridine) onto the surface of silica partially dehydroxylated at 700 °C gives the well-defined silica-supported Ti imido complex (≡SiO)Ti(=NtBu)(Me Pyr)(py) , which is fully characterized by IR and solid-state NMR spectroscopy as well as elemental and mass balance analyses. While stoichiometric imido-transfer reactivity is typical for Ti imides, the obtained surface complex is unique in that it enables catalytic transformations involving Ti imido and oxo intermediates. In particular, it efficiently catalyzes imidation of carbonyl compounds with N-sulfinylamines by oxo/imido heterometathesis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.201804346 | DOI Listing |
Chempluschem
August 2024
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334, Moscow, Russia.
Continuing our investigation of catalytic oxo/imido heterometathesis as novel water-free method for C=N bond construction, we report here the application of classical transition metal oxides dispersed on silica (MO/SiO, M=V, Mo, W) as cheap, robust and readily available alternative to the catalysts prepared via Surface Organometallic Chemistry (SOMC). The oxide materials demonstrated activity in heterometathetical imidation of ketones, WO/SiO being the most efficient. We also describe a new well-defined supported W imido complex (≡SiO)W(=NMes)(MePyr) (Mes=2,4,6-MeCH, MePyr=2,5-dimethylpyrrolyl) and characterize it with SOMC protocols, which allowed us to identify the position of W on the oxo/imido heterometathesis activity scale (Mo
Dalton Trans
March 2024
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119334 Moscow, Russia.
We investigate Ti(NEt) supported on silica dehydroxylated at 700 °C as an easily accessible pre-catalyst for oxo/imido heterometathesis reactions. Being activated with TolNH, the supported Ti amide (SiO)Ti(NEt) (1) demonstrates catalytic activity in the imidation of ketones with -sulfinylamines comparable with the most active previously described well-defined imido catalyst (SiO)Ti(NBu)(MePyr)(py) (2) (MePyr = 2,5-dimethylpyrrolyl), which implies the formation of surface imido species in this system. The materials obtained treatment of 1 with anilines (TolNH (1a) and -MeOCHNH (1b)) were studied with IR, EA and H, C, N and 2D solid-state NMR, although the proposed imido intermediate has not been detected, pointing towards tris-amides (SiO)Ti(NHCHX) (X = Me, OMe) being the major surface species in the isolated materials 1a and 1b.
View Article and Find Full Text PDFChem Commun (Camb)
March 2021
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, Moscow 119991, Russia.
We report the first examples of direct imidation of lactones giving the corresponding cyclic imidates via oxo/imido heterometathesis with N-sulfinylamines catalysed by a well-defined silica-supported Ti imido complex.
View Article and Find Full Text PDFChem Rev
February 2019
Chemical Sciences & Engineering Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States.
The chemistry of vanadium has seen remarkable activity in the past 50 years. In the present review, reactions catalyzed by homogeneous and supported vanadium complexes from 2008 to 2018 are summarized and discussed. Particular attention is given to mechanistic and kinetics studies of vanadium-catalyzed reactions including oxidations of alkanes, alkenes, arenes, alcohols, aldehydes, ketones, and sulfur species, as well as oxidative C-C and C-O bond cleavage, carbon-carbon bond formation, deoxydehydration, haloperoxidase, cyanation, hydrogenation, dehydrogenation, ring-opening metathesis polymerization, and oxo/imido heterometathesis.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2018
Laboratory for Organometallic Compounds, A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str., 28, 119991, Moscow, Russia.
Grafting Ti(=NtBu)(Me Pyr) (py) (Me Pyr= 2,5-dimethylpyrrolyl, py=pyridine) onto the surface of silica partially dehydroxylated at 700 °C gives the well-defined silica-supported Ti imido complex (≡SiO)Ti(=NtBu)(Me Pyr)(py) , which is fully characterized by IR and solid-state NMR spectroscopy as well as elemental and mass balance analyses. While stoichiometric imido-transfer reactivity is typical for Ti imides, the obtained surface complex is unique in that it enables catalytic transformations involving Ti imido and oxo intermediates. In particular, it efficiently catalyzes imidation of carbonyl compounds with N-sulfinylamines by oxo/imido heterometathesis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!