X-Ray Structure of a Heterochiral, Sulfoximine-Stabilized Dilithiomethane Derivative

Müller, Jürgen; Neuburger, Markus; Spingler, Bernhard

doi:10.1002/(sici)1521-3773(19991203)38:23<3549::aid-anie3549>3.0.co;2-d

Cited by 33 publications

(3 citation statements)

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“…The presence of Li 2 O, generated in situ by hydrolysis of H 2 O added on purpose, allowed crystallization and thus separation of the dianion from excess base, although in poor yield (17%). 15 Chiral geminal-dianions could lead to interesting developments in organic synthesis. Indeed, the two Li atoms are diastereotopic and selective reactivity at C could lead to the generation of a stereogenic C center.…”

Section: Scheme 5: "Type I" Geminal Dianions For Which X-ray Structure Is Known (1985-2012)mentioning

confidence: 99%

“…Again, an excess of n-BuLi (2.5 equiv) was used to favor double deprotonation. The presence of Li 2 O, generated in situ by hydrolysis of H 2 O added on purpose, allowed crystallization and thus separation of the dianion from excess base, although in poor yield (17%) . Chiral geminal-dianions could lead to interesting developments in organic synthesis.…”

Section: Geminal Dianions Of Type I (A and B: Neutral Fragments)mentioning

confidence: 99%

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Geminal Dianions Stabilized by Main Group Elements

2019

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This review is dedicated to the chemistry of stable and isolable species that bear two lone pairs at the same C center, i.e. geminal dianions, stabilized by main group elements. Three cases can thus be considered: the gem dilithio derivative, for which the two substituents at C are neutral, the ylidiide derivatives, for which one substituent is neutral while the other is charged, and finally the geminal bisylides, for which the two substituents are positively charged. In this review the syntheses and electronic structures of the geminal dianions are presented, followed by the studies dedicated to their reactivity toward organic substrates and finally to their coordination chemistry and applications. Reactivity of doubleylides towards organic compounds. 4.4. Coordination chemistry of double ylides to metallic species. 4.4.1. Coordination to Group 2 Metals. 4.4.2. Coordination to Actinides: Uranium Complexes 4.4.3. Coordination to Group 4 Metals: Zirconium Complexes 4.4.4. Coordination to Group 6 Metals: Tungsten Complexes 4.4.5. Coordination to Group 7 Metals: Manganese and Rhenium Complexes 4.4.6. Coordination to Group 8 Metals: Iron Complexes 4.4.7. Coordination to Group 9 Metals: Rhodium and Iridium Complexes 4.4.8. Coordination to Group 10 Metals 4.4.9. Coordination to Group 11 (Coinage) Metals 4.4.10. Coordination to Group 12 Metals 4.5. Reactivity of double ylides towards main group elements. 4.5.1. Group 13 4.5.2. Group 14 4.5.3. Group 15 4.5.4. Group 16 4.5.5. Group 17 4.6. Carbodicarbenes 4.6.1. Synthesis 4.6.2. Reactivity 4.6.3. Coordination chemistry 4.6.4. Reactivity with main group elements 5. Conclusion 6. Acknowledgements 7. References lengths in complexes [(7)Mg(THF)] 2 and [(14)Mg(THF) 3 ] at 2.156(5)Å and 2.113(4)Å resp. are as expectedly significantly shorter than the ones measured in the dimers [(6a)Mg] 2 and [(10)Mg] 2 at 2.225(2)Å (av.) and 2.267(3)Å (av.). Electronic structureThe question of the nature of the bond between the AE metal and C was addressed. Harder et al.performed a DFT study first on models of [(6a)Ca] 2 and [(6f)Ca] where H atoms were considered in place of the real phenyl groups at P and groups (SiMe 3 and Ar resp.) at N. 49 In the case of the monomeric complex [(6f)Ca], the solvent molecules were not taken into account. Not surprising in light of the difference of electronegativity of the elements, the charge at C varied between -1.623 (monomer) and -1.847 (dimer) whereas charge at Ca varied between +1.760 (monomer) and +1.821 (dimer). The Ca-C bond was thus described as highly ionic. The calculations with the full dimeric system were carried out, and a slightly reduced charge was calculated at C (-1.778). The NPA charges were also compared to the ones in neutral 6aH 2 and the [Ca(6aH) 2 ] complex. Expectedly the charge at C goes from -1.079 to -1.409 to -1.778 (in 6aH2, [Ca(6aH) 2 ], [Ca(6a)] 2 resp.). The charge at N also increases (-1.474 to -1.580 to -1.665 resp.) upon deprotonation at C. Conversely, the charge at P varies but to a small extent (+1.747 to +1.727 to +1.7...

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Section: Scheme 5: "Type I" Geminal Dianions For Which X-ray Structure Is Known (1985-2012)mentioning

confidence: 99%

Section: Geminal Dianions Of Type I (A and B: Neutral Fragments)mentioning

confidence: 99%

Geminal Dianions Stabilized by Main Group Elements

2019

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“…29,37 Both, the structure of [Si(NLiCH 3 ) 2 (N(CH 3 ) 2 )] 4 29 and that of [Li 2 (THF) 0.5 {(C R ,C R /C S ,C S )-2-P(2,4,6-iPr 3 C 6 H 2 )-1-O-cyclo-C 6 H 10 }] 4 37 consist of a similar octanuclear core of the type Li 8 N 8 and Li 8 O 4 P 4 , respectively. Furthermore, a literature search for compounds containing eight-membered Li 4 N 4 squares with linear N-Li-N bonds as found in 3a gave only a very limited amount of hits [38][39][40] demonstrating the unusual structural situation in 3a.…”

Section: Preparation Of Tris(dimethylamino)anilinosilane (1)mentioning

confidence: 99%

Preparation and Solid State Structures of Tetra(amino)silane Organolithium Compounds Containing a Li₈ Core Forming a Johnson Solid J26 and a Li₄ Core

et al. 2008

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Tris(dimethylamino)silyl substituted aniline HNPh{Si(NMe2)3} (1) was prepared in high yield by metathesis reaction of lithium anilide with tris(dimethylamino)chlorosilane. 1 reacts with 1 equiv of n-butyl lithium at elevated temperatures to yield the corresponding lithium salt [LiNPh{Si(NMe2)3}] (2). Treatment of 1 with 2 equiv of n-butyl lithium leads to dilithiated compounds [Li2N(C6H4){Si(NMe2)3}]4 (3a) or [Li2(THF)2N(C6H4){Si(NMe2)3}]2 (3b) depending on the solvent used for crystallization, the former being crystallized in heptane, the latter in tetrahydrofuran (THF). Single crystal analyses of 3a and 3b confirm the occurrence of two lithium atoms per ligand, where the anilino nitrogen atom and one ortho carbon atom of the phenyl group are deprotonated. In both cases organolithium compounds with polynuclear lithium cores are formed. The molecular structure of 3a represents the first example of an organolithium compound consisting of a Li8 core that forms a polyhedron in which two trigonal prisms share one square face and are twisted by 90 degrees. Such a polyhedron is known in mathematics as the Johnson solid J26 or as Gyrobifastigium and is rare in chemistry. The coordinating carbon atoms are situated above the other square faces with three close contacts and one slightly longer contact to four lithium atoms. Furthermore, the central four lithium atoms form an Li4N4 square with almost linear N-Li-N bonds, a rare structural situation. The molecular structure of 3b shows each lithium atom to be additionally coordinated by a molecule of THF compared to that of 3a. Thus, a dimeric structure is found with a Li4 core that forms a planar parallelogram. The carbon atoms are found in close contact to a triangular Li3 face on each side of the Li4 plane.

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Chiral Dilithiomethane Derivatives: Structure Determination and Application in Stereoselective Reactions

Müller

2000

Eur. J. Inorg. Chem.

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The synthesis and X‐ray analysis of chiral dilithiomethane analogues derived from sulfoximines are presented. The structures of the sulfoximine‐stabilised mono‐ and dilithio salts have been compared and allow a rationalization of the second lithiation. Organophosphorus‐based dilithiomethane derivatives are also structurally described. The gas‐phase structures of N,S,S‐trimethylsulfoximine 19 and of its mono‐ and dilithiated isomers 20–21 were calculated by ab initio methods employing different levels of theory. For an application in asymmetric synthesis, the dilithiation of (N‐methyl)‐S‐ethyl‐S‐phenylsulfoximine (11) afforded a chiral dinucleophile that undergoes highly regio‐ and stereoselective alkylation reactions with electrophiles. The transmetallation of a chiral dilithiomethane reagent such as 14 with ClTi(OiPr)3 followed by addition of an aldehyde, constitutes a simple one‐pot process for the formation of (E)‐alkenylsulfoximines with excellent diastereoselectivity.

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X-Ray Structure of a Heterochiral, Sulfoximine-Stabilized Dilithiomethane Derivative

Cited by 33 publications

References 3 publications

Geminal Dianions Stabilized by Main Group Elements

Geminal Dianions Stabilized by Main Group Elements

Preparation and Solid State Structures of Tetra(amino)silane Organolithium Compounds Containing a Li₈ Core Forming a Johnson Solid J26 and a Li₄ Core

Chiral Dilithiomethane Derivatives: Structure Determination and Application in Stereoselective Reactions

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X-Ray Structure of a Heterochiral, Sulfoximine-Stabilized Dilithiomethane Derivative

Cited by 33 publications

References 3 publications

Geminal Dianions Stabilized by Main Group Elements

Geminal Dianions Stabilized by Main Group Elements

Preparation and Solid State Structures of Tetra(amino)silane Organolithium Compounds Containing a Li8 Core Forming a Johnson Solid J26 and a Li4 Core

Chiral Dilithiomethane Derivatives: Structure Determination and Application in Stereoselective Reactions

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Preparation and Solid State Structures of Tetra(amino)silane Organolithium Compounds Containing a Li₈ Core Forming a Johnson Solid J26 and a Li₄ Core