Lithiation of lithium (2-pyridylmethyl)(tert-butyldimethylsilyl)amide – synthesis and structural characterization of a 1,2-dilithiated (2-pyridylmethyl)(tert-butyldimethylsilyl)amine

The reaction of (thf)Fe[N(SiMe3)2]2Cl with (2‐pyridylmethyl)(diphenylphosphanyl)amine (1) in hot tetrahydrofuran (THF) yields dinuclear [(ClFe)2{μ‐N(SiMe3)2}{Ph2P(NCH2Py)2}] (2) and [ClFe{Ph2P(O)‐NCH2Py}]2 (3) with the oxygen atom stemming from THF degradation. The formation of 2 requires a P–N bond cleavage and reformation leading to the tetradendate diphenyl‐bis(2‐pyridylmethylamido)phosphonium ion. If this reaction of (thf)Fe[N(SiMe3)2]2Cl with 1 is performed at room temperature, no P–N bond cleavage is observed. Instead of that, ether degradation occurs yielding [Fe4(μ4‐O)(μ2‐Cl)2(Ph2P‐NCH2Py)4] (4) with a central oxygen‐centered iron tetrahedron as well as complex 3. Recrystallization of 3 from dichloromethane leads to addition of HCl and to the formation of [FeCl2·{Ph2P(O)‐N(H)‐CH2Py}] (5). The phosphonium ion of 2 is isoelectronic to the corresponding diphenyl‐bis(2‐pyridylmethylamino)silane (6). Lithiation of 6 followed by a metathetical reaction with (thf)2FeCl2 yields the trinuclear complex [Fe3Cl2{Ph2Si(NCH2Py)2}2] (7) with antiferromagnetic interactions.

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“…[10] These dianions (L) 2-can be oxidized with e.g. white phosphorus [11] leading to the formation of (L ox1 ) -.…”

Section: P(o)-n(h)-ch 2 Py}] (5)mentioning

confidence: 99%

Influence of N‐Substitution on the Oxidation of 2‐Pyridylmethylamines with Bis(trimethylsilyl)amides of Iron(III) – Synthesis of Heteroleptic Iron(II) 2‐Pyridylmethylamides

et al. 2011

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“…C-Substitution of (2-pyridylmethyl)amine can be achieved by reaction of (2-pyridylmethyl)(trialkylsilyl)-amine with n-butyllithium giving [lithium (2-pyridylmethyl)(trialkylsilyl)amide] [21] and thereafter with benzophenone yielding dimeric 1-lithoxy-1,1-diphenyl-2-(2-pyridyl)-2-(trialkylsilylamino)ethane (1) according to Equation (5). This compound is also accessible by reaction of doubly lithiated (2-pyridylmethyl)(trialkylsilyl)amine [21] with benzophenone and subsequent partial hydrolysis. [22] The solid-state structure of 1 was determined in order to clarify the coordination behaviour of this tridentate ligand.…”

Section: Synthesismentioning

confidence: 99%

Lithium and Zinc Complexes of C‐ and N‐Functionalized (2‐Pyridylmethyl)amines

et al. 2008

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The addition reaction of benzophenone with lithium (2‐pyridylmethyl)(tert‐butyldimethylsilyl)amide yields dimeric1‐lithoxy‐1,1‐diphenyl‐2‐(2‐pyridyl)‐2‐(trialkylsilylamino)ethane (1) with formation of a C–C bond. C‐Functionalized 2‐(pyridylmethyl)amines are accessible via the reaction of N‐(2‐pyridylmethylidene)phenylamine with diethylmalonate giving 2,2‐bis(ethoxycarbonyl)‐1‐(phenylamino)‐1‐(2‐pyridyl)ethane (2) which eliminates aniline upon heating yielding diethyl 2‐(2‐pyridylmethylidene)malonate (3). The addition of piperidine leads to the formation of the Michael type adduct 2,2‐bis(ethoxycarbonyl)‐1‐piperidyl‐1‐(2‐pyridyl)ethane (4) which can be deprotonated with metal‐organic reagents such as Zn[N(SiMe3)2]2, Zn[CH(SiMe3)2]2, LiN(SiMe3)2, and NaN(SiMe3)2 leading to 2,2‐bis(ethoxycarbonyl)‐1‐piperidyl‐1‐(2‐pyridyl)ethane‐2‐yl complexes of zinc (5 and 6), lithium (7), and sodium (8). N‐Functionalization can be achieved via the reaction of (2‐pyridylmethyl)(trialkylsilyl)amine with benzoyl chloride giving N‐(2‐pyridylmethyl)benzoylamine (9). Lithiation and subsequent salt metathesis reaction with another equivalent of benzoyl chloride yields N‐(2‐pyridylmethyl)dibenzoylamine (10). The addition reaction of ZnCl2 with N‐(2‐pyridylmethyl)(diphenylmethylidene)amine (11) forms colorless crystalline [(Py–CH2N=CPh2)ZnCl2] (12). The addition of benzoyl chloride leads to N‐(diphenylchloromethyl)‐N‐(2‐pyridylmethyl)benzoylamine (13). Addition of ZnCl2 leads to the formation of solvent‐separated [(2‐pyridylmethyl)(benzoylamino)diphenylcarbonium] [(tetrahydrofuran)trichlorozincate] (14). The X‐ray crystal structures of 1, 4 to 7, 9, 12, and 14 are discussed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

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“…Single and double deprotonations of (H 2 L) lead to the formation of amides (HL) À (deprotonation of the amino group) and bisamides (L) 2À (deprotonation at the methylene fragment and delocalization of the anionic charge into the pyridyl unit), respectively. Whereas the amides (HL) À represent widely used ligands, the doubly metallated amines are only stable as salts with cations of very electropositive metals such as lithium [1] and magnesium [2]. Nobler metals such as tin(II) and zinc(II) initiate a single electron transfer reaction yielding the radical anion (L ox1 ) À , which can dimerize to CeC coupled (L ox1 2 ) 2À , and elemental metal.…”

Section: Introductionmentioning

confidence: 99%

Deprotonation and dehydrogenation of Di(2-pyridylmethyl)amine with M[N(SiMe3)2]2 (M = Mn, Fe, Co, Zn) and Fe(C6H2-2,4,6-Me3)2

Malassa

Agthe

Görls

et al. 2010

Journal of Organometallic Chemistry

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Lithiation of lithium (2-pyridylmethyl)(tert-butyldimethylsilyl)amide – synthesis and structural characterization of a 1,2-dilithiated (2-pyridylmethyl)(tert-butyldimethylsilyl)amine

Cited by 13 publications

References 11 publications

Influence of N‐Substitution on the Oxidation of 2‐Pyridylmethylamines with Bis(trimethylsilyl)amides of Iron(III) – Synthesis of Heteroleptic Iron(II) 2‐Pyridylmethylamides

Influence of N‐Substitution on the Oxidation of 2‐Pyridylmethylamines with Bis(trimethylsilyl)amides of Iron(III) – Synthesis of Heteroleptic Iron(II) 2‐Pyridylmethylamides

Lithium and Zinc Complexes of C‐ and N‐Functionalized (2‐Pyridylmethyl)amines

Deprotonation and dehydrogenation of Di(2-pyridylmethyl)amine with M[N(SiMe3)2]2 (M = Mn, Fe, Co, Zn) and Fe(C6H2-2,4,6-Me3)2

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