DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: β-SiH-containing tris(silazido) rare-earth complexes as homogeneous and grafted single-site catalyst precursors for hydroamination

Journal Article · · Organometallics

A series of homoleptic rare-earth silazido compounds and their silica-grafted derivatives were prepared to compare spectroscopic and catalytic features under homogeneous and interfacial conditions. Trivalent tris(silazido) compounds Ln{N(SiHMe2)tBu}3 (Ln = Sc (1), Y (2), Lu (3)) are prepared in high yield by salt metathesis reactions. Solution-phase and solid-state characterization of 1–3 by NMR and IR spectroscopy and X-ray diffraction reveals Ln←H–Si interactions. These features are retained in solvent-coordinated 2·Et2O, 2·THF, and 3·THF. The change in spectroscopic features characterizing the secondary interactions (νSiH, 1JSiH) from the unactivated SiH in the silazane HN(SiHMe2)tBu follows the trend 3 > 2 > 1 ≈ 2·Et2O > 2·THF ≈ 3·THF. Ligand lability follows the same pattern, with Et2O readily dissociating from 2·Et2O while THF is displaced only during surface grafting reactions. 1 and 2·THF graft onto mesoporous silica nanoparticles (MSN) to give Ln{N(SiHMe2)tBu}n@MSN (Ln = Sc (1@MSN), Y (2@MSN)) along with THF and protonated silazido as HN(SiHMe2)tBu and H2NtBu. The surface species are characterized by multinuclear and multidimensional solid-state (SS) NMR spectroscopic techniques, as well as diffuse reflectance FTIR, elemental analysis, and reaction stoichiometry. A key 1JSiH SSNMR measurement reveals that the grafted sites most closely resemble Ln·THF adducts, suggesting that siloxane coordination occurs in grafted compounds. These species catalyze the hydroamination/bicyclization of aminodialkenes, and both solution-phase and interfacial conditions provide the bicyclized product with equivalent cis:trans ratios. As a result, similar diastereoselectivities mediated by catalytic sites under the two conditions suggest similar effective environments.

Research Organization:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC02-07CH11358
OSTI ID:
1349902
Report Number(s):
IS-J-9244
Journal Information:
Organometallics, Vol. 36, Issue 6; ISSN 0276-7333
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 24 works
Citation information provided by
Web of Science

References (71)

Synthesis and structural characterisation of the first neutral homoleptic lanthanide metal(III) alkyls: [LnR3][Ln = La or Sm, R = CH(SiMe3)2] journal January 1988
Crystal and Molecular Structures of Hexamethyltungsten and Hexamethylrhenium journal February 1996
Preparation and Structures of [W(CH3)6], [Re(CH3)6], [Nb(CH3)6]−, and [Ta(CH3)6]− journal September 1998
Structural Dichotomy in Six-Coordinate d 0 Complexes:  Trigonal Prismatic ( t Bu 3 SiC⋮C) 6 Ta - and Octahedral ( t Bu 3 SiC⋮C) 6 M 2- (M = Zr, Hf) journal October 1998
Homogeneous and Heterogeneous Catalysis: Bridging the Gap through Surface Organometallic Chemistry journal January 2003
Mono- and Dinuclear Silica-Supported Titanium(IV) Complexes and the Effect of TiOTi Connectivity on Reactivity journal August 1999
Spontaneous Evolution of Silica-Supported Ti Amide Fragments to Imine and Imido Complexes journal January 2001
Immobilization of η 5 -cyclopentadienyltris(dimethylamido)zirconium polymerization catalysts on a chlorosilane- and HMDS-modified mesoporous silica surface: a new concept for supporting metallocene amides towards heterogeneous single-site-catalysts journal May 2001
Well-Defined Single-Site Monohydride Silica-Supported Zirconium from Azazirconacyclopropane journal January 2015
Isolation and Characterization of Well-Defined Silica-Supported Azametallacyclopentane: A Key Intermediate in Catalytic Hydroaminoalkylation Reactions journal September 2015
Well-defined azazirconacyclopropane complexes supported on silica structurally determined by 2D NMR comparative elucidation journal January 2013
Mesoporous Silica-Supported Amidozirconium-Catalyzed Carbonyl Hydroboration journal November 2015
Homoleptic Rare-Earth Metal Complexes Containing Ln−C σ-Bonds journal October 2010
Three-co-ordination in lanthanide chemistry: tris[bis(trimethylsilyl)amido]lanthanide(III) compounds journal January 1972
Low co-ordination numbers in lanthanide and actinide compounds. Part I. The preparation and characterization of tris{bis(trimethylsilyl)-amido}lanthanides journal January 1973
Three-co-ordinate scandium(III) and europium(III); crystal and molecular structures of their trishexamethyldisilylamides journal January 1973
Synthesis and structural characterisation of rare-earth bis(dimethylsilyl)amides and their surface organometallic chemistry on mesoporous MCM-41 † journal January 1998
Europium bis(dimethylsilyl)amides including mixed-valent Eu 3 [N(SiHMe 2 ) 2 ] 6 [μ-N(SiHMe 2 ) 2 ] 2 journal January 2014
Homoleptic Lanthanide Amides as Homogeneous Catalysts for Alkyne Hydroamination and the Tishchenko Reaction journal July 2001
Homoleptic Lanthanide Alkyl and Amide Precatalysts Efficiently Mediate Intramolecular Hydrophosphination/Cyclization. Observations on Scope and Mechanism journal November 2003
Effective, Selective Hydroalkoxylation/Cyclization of Alkynyl and Allenyl Alcohols Mediated by Lanthanide Catalysts journal June 2007
Mild Amidation of Aldehydes with Amines Mediated by Lanthanide Catalysts journal January 2008
The Danishefsky Hetero Diels–Alder Reaction Mediated by Organolanthanide-Modified Mesoporous Silicate MCM-41 journal March 1999
Organometallic chemistry on periodic mesoporous organosilicas: generation of surface-confined zinc and yttrium centres journal January 2006
Grafted lanthanide amides: Versatile catalysts for various transformations journal September 2006
Well-Defined Silica-Supported Rare-Earth Silylamides journal February 2007
Intramolecular Hydroamination/Cyclization of Aminoalkenes Catalyzed by Ln[N(SiMe 3 ) 2 ] 3 Grafted onto Periodic Mesoporous Silicas journal November 2010
Heterogenized “Ligand-Free” Lanthanide Catalysts for the Homo- and Copolymerization of Ethylene and 1,3-Butadiene journal April 2005
C 2 -Symmetric ansa -Lanthanidocene Complexes. Synthesis via Silylamine Elimination and β-SiH Agostic Rigidity journal April 2000
Synthesis and Catalytic Properties of Phenylene-Bridged Binuclear Organolanthanide Complexes journal January 2008
N,N′-Dibenzosuberyl-1,1′-Binaphthyl-2,2′-diamine: A Highly Effective Supporting Ligand for the Enantioselective Cyclization of Aminoalkenes Catalyzed by Chelating Diamide Complexes of La(III) and Y(III) journal June 2014
Agostic .beta.-silicon-hydrogen interactions in silylamido complexes of zirconocene journal January 1994
Reactions of carbon dioxide and carbon disulfide with .eta.2-silanimine complexes of zirconium: facile deoxygenation and desulfurization reactions journal August 1993
Unusual Si–H Bond Activation and Formation of Cationic Scandium Amide Complexes from a Mono(amidinate)-Ligated Scandium Bis(silylamide) Complex and Their Performance in Isoprene Polymerization journal April 2012
Lewis Base Mediated β-Elimination and Lewis Acid Mediated Insertion Reactions of Disilazido Zirconium Compounds journal September 2013
C–H bond activation of ethylene by a zirconacycle journal January 2013
Structural Characterization of a Tris-Agostic LanthanoidHSi Interaction journal March 1996
.eta.2-Silanimine complexes of zirconocene: synthesis, structure, and reactivity of Cp2Zr(.eta.2-SiMe2:N-tert-Bu)(PMe3) journal February 1991
Structure and reactivity of Cp2Zr(η2-Me2SiNtBu)(CO): An unusual silanimine carbonyl complex with extensive σ-π∗ back-bonding journal January 1995
Nonclassical β-Hydrogen Elimination of Hydrosilazido Zirconium Compounds via Direct Hydrogen Transfer journal May 2012
The Presence and Absence of Agostic Electrostatic Si−H···M Interactions in [M{Me2Si(H)N-t-Bu}] (M = Li, Mg1/2) Species journal December 1997
Hydroamination: Direct Addition of Amines to Alkenes and Alkynes journal September 2008
Zirconium-Catalyzed Desymmetrization of Aminodialkenes and Aminodialkynes through Enantioselective Hydroamination journal January 2015
Organolanthanide-catalyzed hydroamination. A kinetic, mechanistic, and diastereoselectivity study of the cyclization of N-unprotected amino olefins journal January 1992
New Yttrium Complexes Bearing Diamidoamine Ligands as Efficient and Diastereoselective Catalysts for the Intramolecular Hydroamination of Alkenes and Alkynes journal April 2004
Bis- and Mono(amidate) Complexes of Yttrium: Synthesis, Characterization, and Use as Precatalysts for the Hydroamination of Aminoalkenes journal June 2009
Chelating Diamide Based Rate Enhancement of Intramolecular Alkene Hydroaminations Catalyzed by a Neutral Sc(III) Complex journal September 2005
Intramolecular Hydroamination of Aminoalkenes Catalyzed by a Cationic Zirconium Complex journal September 2011
Intramolecular hydroamination reactions catalyzed by zirconium complexes bearing bridged bis(phenolato) ligands journal January 2016
Enantiospecific Synthesis of Heterocycles from α-Amino Acids journal January 1996
Synthesis of New Bridgehead Substituted Azabicyclo-[2.2.1]heptane and -[3.3.1]nonane Derivatives as Potent and Selective α7 Nicotinic Ligands journal November 2010
Substituted azabicyclo[2.2.1]heptanes via nitrenium ion rearrangement journal February 2012
Synthesis of 2-aminomethyl-4-phenyl-1-azabicyclo[2.2.1]heptanes via LiAlH4-induced reductive cyclization of 2-(4-chloro-2-cyano-2-phenylbutyl)aziridines and evaluation of their antimalarial activity journal March 2013
Synthesis and reactions of silyl and germyl derivatives of scandocene. Structure of Cp2Sc[Si(SiMe3)3](THF) journal July 1993
Synthesis and Characterization of Scandium Silyl Complexes of the Type Cp* 2 ScSiHRR‘. σ-Bond Metathesis Reactions and Catalytic Dehydrogenative Silation of Hydrocarbons journal January 2005
Matrix Infrared Spectra and DFT Calculations of the Reactive MH x ( x = 1, 2, and 3), (H 2 )MH 2 , MH 2 + , and MH 4 - (M = Sc, Y, and La) Species journal October 2002
The molecular structrure of gaseous tris(bis(trimethylsilyl) amido)scandium, Sc{N(Si(CH3)3)2}3, as determined by electron diffraction: A three-coordinate scandium(III) amide journal April 1985
Silylation Efficiency of Chorosilanes, Alkoxysilanes, and Monosilazanes on Periodic Mesoporous Silica journal December 2010
Surface Functionality of Amorphous Silica by Infrared Spectroscopy journal October 1958
Surface vibrational modes of silanol groups on silica journal February 1992
Infrared and gravimetric study of an aerosil and a precipitated silica using chemical and hydrogen/deuterium exchange probes journal August 1991
Surface organometallic chemistry: synthesis and characterization of a tris(neopentyl)zirconium(IV) complex grafted to the surface of a partially dehydroxylated silica journal March 1992
Sensitivity Enhancement in Solid State 15N NMR by Indirect Detection with High-Speed Magic Angle Spinning journal January 2000
Chemical Shift Correlation NMR Spectroscopy with Indirect Detection in Fast Rotating Solids:  Studies of Organically Functionalized Mesoporous Silicas
  • Wiench, Jerzy W.; Bronnimann, Charles E.; Lin, Victor S. -Y
  • Journal of the American Chemical Society, Vol. 129, Issue 40, p. 12076-12077 https://doi.org/10.1021/ja074746+
journal September 2007
Carbon-13 nuclear magnetic resonance spectra of acyclic aliphatic amines journal May 1973
Solid-state NMR studies of the reactions of silica surfaces with polyfunctional chloromethylsilanes and ethoxymethylsilanes journal June 1983
Observation of a H-Agostic Bond in a Highly Active Rhenium–Alkylidene Olefin Metathesis Heterogeneous Catalyst by Two-Dimensional Solid-State NMR Spectroscopy journal December 2002
Frequency-switched pulse sequences: Homonuclear decoupling and dilute spin NMR in solids journal March 1989
High-Speed Magic-Angle Spinning13C MAS NMR Spectra of Adamantane: Self-Decoupling of the Heteronuclear Scalar Interaction and Proton Spin Diffusion journal February 1998
Base-catalysed asymmetric hydroamination/cyclisation of aminoalkenes utilising a dimeric chiral diamidobinaphthyl dilithium salt journal January 2006
Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides journal September 1976

Cited By (2)

Synthesis of well-defined yttrium-based Lewis acids by capturing a reaction intermediate and catalytic application for cycloaddition of CO 2 to epoxides under atmospheric pressure journal January 2019
Rare earth arylsilazido compounds with inequivalent secondary interactions journal January 2018


Figures / Tables (15)