Alexander N Erickson, Curtis Haltiwanger, Masoumeh Rahim, Charles M Garner
{"title":"Preferential crystallization of (±)-pinenyllithium·TMEDA.","authors":"Alexander N Erickson, Curtis Haltiwanger, Masoumeh Rahim, Charles M Garner","doi":"10.1107/S2053229624004662","DOIUrl":null,"url":null,"abstract":"<p><p>(±)-Pinenyllithium·TMEDA or (tetramethylethylenediamine-κ<sup>2</sup>N,N')(η<sup>3</sup>-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptyl)lithium, [Li(C<sub>10</sub>H<sub>15</sub>)(C<sub>6</sub>H<sub>16</sub>N<sub>2</sub>)], is readily prepared from β-pinene, butyllithium and TMEDA, and the racemic material preferentially crystallizes even from 96:4 (92% ee) mixtures of (-)- and (+)-β-pinene, respectively. The structure is monomeric, with the geminal-dimethyl bridge of the bicyclic structure shielding one face of the allyl system, restricting the lithium to the opposite face and preventing the Li-allyl-Li aggregation observed with some other allyllithium systems. The symmetry of the allyl system, bond lengths, bond angles and out-of-plane deviations are compared to existing structures. In addition, a much older structure of this complex is compared to this very recent one.</p>","PeriodicalId":7115,"journal":{"name":"Acta Crystallographica Section C Structural Chemistry","volume":null,"pages":null},"PeriodicalIF":0.7000,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11225615/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Crystallographica Section C Structural Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1107/S2053229624004662","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/6/19 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
(±)-Pinenyllithium·TMEDA or (tetramethylethylenediamine-κ2N,N')(η3-6,6-dimethyl-2-methylenebicyclo[3.1.1]heptyl)lithium, [Li(C10H15)(C6H16N2)], is readily prepared from β-pinene, butyllithium and TMEDA, and the racemic material preferentially crystallizes even from 96:4 (92% ee) mixtures of (-)- and (+)-β-pinene, respectively. The structure is monomeric, with the geminal-dimethyl bridge of the bicyclic structure shielding one face of the allyl system, restricting the lithium to the opposite face and preventing the Li-allyl-Li aggregation observed with some other allyllithium systems. The symmetry of the allyl system, bond lengths, bond angles and out-of-plane deviations are compared to existing structures. In addition, a much older structure of this complex is compared to this very recent one.
期刊介绍:
Acta Crystallographica Section C: Structural Chemistry is continuing its transition to a journal that publishes exciting science with structural content, in particular, important results relating to the chemical sciences. Section C is the journal of choice for the rapid publication of articles that highlight interesting research facilitated by the determination, calculation or analysis of structures of any type, other than macromolecular structures. Articles that emphasize the science and the outcomes that were enabled by the study are particularly welcomed. Authors are encouraged to include mainstream science in their papers, thereby producing manuscripts that are substantial scientific well-rounded contributions that appeal to a broad community of readers and increase the profile of the authors.