Synthesis of mono- and geminal dimetalated carbanions of bis(phenylsulfonyl)methane using alkali metal bases and structural comparisons with lithiated bis(phenylsulfonyl)imides.
The alpha,alpha'-stabilized carbanion complexes [(PhSO2)2CHLi.THF]1, [(PhSO2)2CHNa.THF]2 and [(PhSO2)2CHK]3 were prepared by the direct deprotonation of bis(phenylsulfonyl)methane I in THF with one molar equivalent of MeLi, BuNa and BnK respectively. The geminal dianionic complexes [(PhSO2)2CLi2.THF]4, [(PhSO2)2CNa2.0.55THF]5 and [(PhSO2)2CK2]6 were similarly prepared by the reaction of I with two molar equivalents of MeLi, BuNa and BnK respectively in THF. NMR and MS solution studies of 1-3 are consistent with the formation of charge-separated species in DMSO media. Solutions studies of 4-6, in conjunction with trapping experiments, indicate that the dianions deprotonate DMSO and regenerate the monoanions 1-3. Crystallographic analysis of 1 revealed a 1D chain polymer in which the metal centers are chelated by the bis(sulfonyl) ligands and connect to neighboring units through Li-O(S) interactions. An unexpected feature of 1 is that the polymeric chains are homochiral, since the chelating ligands of the backbone adopt the same relative configuration. Also, the phenyl substituents of each chelate in 1 are oriented in a cisoid manner. The sodium derivative 2 adopts a related solid-state structure, where enantiomeric pairs of chains combine to give a 1D ribbon motif. The lithium bis(phenylsulfonyl)imides [(PhSO2)2NLi.THF]9 and [(PhSO2)2NLi.Pyr2]10 were also prepared and structurally characterized. In the solid state 9 has a similar connectivity to that found for 1 but with heterochiral chains. In comparison, the more highly solvated complex 10 forms a 1D polymeric arrangement without chelation of the ligands and with the phenyl substituents oriented in a transoid fashion.
MacDougall
Dugald J
DJ
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
Kennedy
Alan R
AR
Noll
Bruce C
BC
Henderson
Kenneth W
KW
D002614:Chelating Agents / Q000737:chemistry; D018360:Crystallography, X-Ray; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D007094:Imides / Q000737:chemistry*; D008024:Ligands; D008094:Lithium / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008672:Metals, Alkali / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis*; D013237:Stereoisomerism; D013450:Sulfones / Q000138:chemical synthesis*
D002614:Chelating Agents; D005663:Furans; D007094:Imides; D008024:Ligands; D008672:Metals, Alkali; D009942:Organometallic Compounds; D013450:Sulfones; C517722:bis(phenylsulfonyl)methane; C018674:tetrahydrofuran; D008094:Lithium; D008697:Methane; D004121:Dimethyl Sulfoxide