1-(N-trimethylsilyl-S-phenylsulfonimidoyl)-3-methyl-2-butenyl Lithium·2(12-Crown-4): Structure of a lithiated allylic sulfoximine in the crystal and comparison with model ab initio calculations

Autor:	Dirk Lenz, Gerhard Raabe, Hans-Joachim Gais
Rok vydání:	1995
Předmět:	Allylic rearrangement Trimethylsilyl Stereochemistry Organic Chemistry Crystal structure Biochemistry Negative hyperconjugation chemistry.chemical_compound Crystallography chemistry Ab initio quantum chemistry methods Drug Discovery Lone pair Conformational isomerism Carbanion
Zdroj:	Tetrahedron Letters. 36:7437-7440
ISSN:	0040-4039
DOI:	10.1016/0040-4039(95)01555-8
Popis:	The crystal structures of the lithiated allylic sulfoximine 1a (12-c-4) 2 , which is a solvent separated contact ion pair, and of the allylic sulfoximine 3b were determined. The anion of 1a (12-c-4) 2 adopts a conformation in which the lone pair orbital at the C α -atom is gauche to the O- and the N-atom. The C α -S bond is considerably shortened. Similar to α-sulfonyl carbanions the conformation of α-sulfonimidoyl carbanions seems to be determined by negative hyperconjugation. Ab initio calculations (6–31+G*) of various conformers of the anion 4 ( a–c ) suggest a low configurational stability of the C α -atom of 1 .
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::43a7d0f717ce7bd08de9d39116751b0c https://doi.org/10.1016/0040-4039(95)01555-8 Zobrazit plný text záznamu Full Text from ScienceDirect