[(NHC)Yb{N(SiMe3)2}2]‐Catalyzed Cross‐Dehydrogenative Coupling of Silanes with Amines

Xie, Weilong; Hu, Hongfan; Cui, Chunming

doi:10.1002/ange.201205317

Cited by 25 publications

(5 citation statements)

References 63 publications

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“…As a contrast, tribenzylyttrium complex without an auxiliary ligand was also investigated, which failed to achieve the catalytic dehydrogenative coupling reaction even at elevated temperature (Table , entries 5–6). Similar ligand accelerating effect was also reported by Crimmin and Cui using a phosphorus based ligand and a NHC ligand . Using the yttrium complex ( 2 d ) as catalyst, we further carried out the silylamination reaction of methylphenylsilane ( 3 b ) and tert ‐butylamine.…”

Section: Figuresupporting

confidence: 67%

Yttrium–Benzyl Complexes Bearing Chiral Iminophosphonamide Ligands: Synthesis and Application in Catalytic Asymmetric Amine‐Silane Dehydrocoupling Reactions

Guan

2017

Adv Synth Catal

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A series of novel iminophosphonamide ligands with chiral diamine moieties were designed and synthesized. Yttrium-benzyl compounds bearing these chiral iminophosphonamide ligands showed high reactivity and selectivity on the first catalytic asymmetric cross-dehydrogenative coupling of amines with prochiral silanes under mild conditions. A stable silylamine-boron derivative was synthesized in up to 23% ee, as determined by chiral HPLC analysis. By employing this catalyst system, catalytic kinetic resolution of an axially chiral silane and further in situ allylation were achieved in good yields and enantioselectivities.The past decades have witnessed the development of organosilane compounds, which have been widely used in organic functional materials and bioactive drugs. [1] Optically active silicon stereogenic compounds, however, are not available in nature, probably due to the Berry pseudorotation (BPR) of the highercoordinate silicon atom. [2] Significant progress has been made in creating silicon stereocenters utilizing chiral resolution and asymmetric induction. [3] However, the development of catalytic asymmetric methods using transition-metal catalysts has rarely been explored. Inventive catalytic desymmetrization reactions of prochiral silicon compounds have been developed, such as hydrosilylation of ketones, [4] alkenes [5] and alkynes, [6] carbon silylation of alkynes, [7] and [2 + 2 + 2] cycloaddition. [8] Additionally, enantioselective carbene insertion, [9] alcoholysis, [10] SiÀC cross-coupling, [11] and other desymmetrization reactions [12] have also been established.Silylamines, serving as bases, ligands, silylation agents and polymer precursors, play an important role in synthetic chemistry. [13] In contrast with traditional silylamine synthesis from chlorosilanes and amines, catalytic cross-dehydrogenative coupling of amines and silanes presents an atom-economic approach, with the generation of hydrogen as the only byproduct. Extensive studies have been carried out using metal catalysts, including metal carbonyls, [14] alkali metal complexes, [15] alkaline-earth complexes, [16] rare-earth complexes, [17] group IV metal complexes [18] and other catalysts. [19] However, an asymmetric version has not been introduced into the catalytic cross-dehydrogenative coupling of amines and silanes so far. Herein, we synthesized a series of novel rare-earth and alkalineearth alkyl complexes bearing non-C 2 -symmetric chiral iminophosphonamide ligands, among which yttrium complexes showed good reactivity and selectivity on the first catalytic asymmetric amine À silane dehydrogenative coupling reactions.The iminophosphonamide ligands, being versatile in tuning steric and electronic properties around rareearth metal centers, [20] have found their applications in catalytic polymerization and hydroamination reactions. In order to further explore the catalytic asymmetric potentiality, a chiral diamine moiety (1R, 2R)diaminocyclohexane or (1R,2R)-diphenylethylenediamine was introduced into the iminophosphonamide struct...

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Section: Figuresupporting

confidence: 67%

Yttrium–Benzyl Complexes Bearing Chiral Iminophosphonamide Ligands: Synthesis and Application in Catalytic Asymmetric Amine‐Silane Dehydrocoupling Reactions

Guan

2017

Adv Synth Catal

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“…4,5 Aminosilane compounds have traditionally been synthesised via aminolysis, a process that generates HCl as a side product (eqn (2)). Efforts to provide an alternative route to Si-N bonds using N-H/Si-H dehydrocoupling reactions (eqn (3)) have largely involved catalysts such as (Ph 3 P)RhCl, 6 Cu(I)Cl, 7 (NHC)Yb[N(SiMe 3 ) 2 ] 2 8 (NHC = N-heterocyclic carbene) and [(Et 2 N)U][BPh 4 ]. 9 Apart from the applications of non-metal based Frustrated Lewis Pairs (FLPs), 10 main group catalysed Si-N coupling has so far focused on s-block metal reagents.…”

Section: E-mentioning

confidence: 99%

Stoichiometric and catalytic Si–N bond formation using the p-block base Al(NMe₂)₃

2015

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The aluminium amide Al(NMe2)3 acts as a stoichiometric or catalytic reagent in dehydrogenic Si-N bond formation using amines and silanes. Although of limited substrate scope, this represents the first p-block metal catalytic system for N-H/Si-H dehydrocoupling. The observed catalytic rate law for the formation of aminosilane products in a model study of one of the catalytic reactions suggests a mechanism involving the silane component in the deprotonation of the amine (possibly in the form of a hypervalent silicon hydride).

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“…In this reaction, approximately 2% conversion to Ph{N(SiMe 3 ) 2 }SiH 2 was observed. 18 Neither MePh{N-(SiMe 3 ) 2 }SiH nor Ph 2 {N(SiMe 3 ) 2 }SiH were observed in the reaction between methylphenylsilane or diphenylsilane with diethylamine, respectively. 43 In addition, there are no cases in which bis(trimethylsilyl)amine was coupled with silamine products.…”

Section: ■ Introductionmentioning

confidence: 99%

“…17 In 2012, Cui and co-workers demonstrated that a different ytterbium catalyst, [IMesYb{N(SiMe 3 ) 2 } 2 ] (IMes = 1,3dimesitylimidazol-2-ylidene), could successfully heterodehydrocouple primary and secondary silanes with amines. 18 Sadow has expanded upon Si−N coupling with lanthanides, reporting that [Ln{C(SiHMe 2 ) 3 } 2 ImtBu] (Ln = Yb, Sm; ImtBu = 1,3-ditert-butylimidazol-2-ylidene) are also active catalysts for this transformation. 19 To date, however, there are no reports of more abundant lanthanides catalyzing the heterodehydrocoupling of silanes and amines.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Compound 1 and the reported lanthanide-based catalysts, Cui's [IMesYb{N(SiMe 3 ) 2 } 2 ] catalyst (2) 18 and Sadow's [Ln{C(SiHMe 2 ) 3 } 2 ImtBu] (Ln = Yb (3a), Sm (3b)) catalysts, 19 demonstrate excellent reactivity in the coupling of silanes with isopropylamine (Table 4). For the generation of PhSi( i PrNH) 3 , it is evident that 1 is the most active catalyst, nearly doubling the TOF and TOF SiN as compared to the next most active catalyst.…”

Section: ■ Introductionmentioning

confidence: 99%

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Si–N Heterodehydrocoupling with a Lanthanide Compound

Cibuzar

Waterman

2018

Organometallics

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La{N(SiMe 3 ) 2 } 3 THF 2 ] (1) is an effective precatalyst for the heterodehydrocoupling of silanes and amines. Coupling of primary and secondary amines with aryl silanes was achieved with a loading of 0.8 mol % of [La{N(SiMe 3 ) 2 } 3 THF 2 ]. With primary amines, generation of tertiary and sometimes quaternary silamines was facile, often requiring only a few hours to reach completion, including new silamines Ph 3 Si( n PrNH) and Ph 3 Si( i PrNH). Secondary amines were also available for heterodehydrocoupling, though they generally required longer reaction times and, in some instances, higher reaction temperatures. This work expands upon the utility of f-block complexes in heterodehydrocoupling catalysis.

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[(NHC)Yb{N(SiMe₃)₂}₂]‐Catalyzed Cross‐Dehydrogenative Coupling of Silanes with Amines

Cited by 25 publications

References 63 publications

Yttrium–Benzyl Complexes Bearing Chiral Iminophosphonamide Ligands: Synthesis and Application in Catalytic Asymmetric Amine‐Silane Dehydrocoupling Reactions

Yttrium–Benzyl Complexes Bearing Chiral Iminophosphonamide Ligands: Synthesis and Application in Catalytic Asymmetric Amine‐Silane Dehydrocoupling Reactions

Stoichiometric and catalytic Si–N bond formation using the p-block base Al(NMe₂)₃

Si–N Heterodehydrocoupling with a Lanthanide Compound

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[(NHC)Yb{N(SiMe3)2}2]‐Catalyzed Cross‐Dehydrogenative Coupling of Silanes with Amines

Cited by 25 publications

References 63 publications

Yttrium–Benzyl Complexes Bearing Chiral Iminophosphonamide Ligands: Synthesis and Application in Catalytic Asymmetric Amine‐Silane Dehydrocoupling Reactions

Yttrium–Benzyl Complexes Bearing Chiral Iminophosphonamide Ligands: Synthesis and Application in Catalytic Asymmetric Amine‐Silane Dehydrocoupling Reactions

Stoichiometric and catalytic Si–N bond formation using the p-block base Al(NMe2)3

Si–N Heterodehydrocoupling with a Lanthanide Compound

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[(NHC)Yb{N(SiMe₃)₂}₂]‐Catalyzed Cross‐Dehydrogenative Coupling of Silanes with Amines

Stoichiometric and catalytic Si–N bond formation using the p-block base Al(NMe₂)₃