Synthesis, including asymmetric synthesis, of 1-substituted cyclopentenes from cyclobutanones with one-carbon ring-expansion by 1,2-carbon-carbon insertion of magnesium carbenoids

Autor:	Yu Awata, Shingo Ogata, Shimpei Sugiyama, Hideki Saitoh, Masashi Ishigaki, Tsuyoshi Satoh, Yuichi Kato
Rok vydání:	2011
Předmět:	Magnesium Organic Chemistry Enantioselective synthesis chemistry.chemical_element Sulfoxide Biochemistry Medicinal chemistry chemistry.chemical_compound chemistry Insertion reaction Drug Discovery Organic chemistry Lithium Enantiomeric excess Carbenoid Carbanion
Zdroj:	Tetrahedron. 67:1102-1113
ISSN:	0040-4020
DOI:	10.1016/j.tet.2010.12.023
Popis:	Treatment of 1-chlorovinyl p-tolyl sulfoxides, which were derived from cyclobutanones and chloromethyl p-tolyl sulfoxide, with lithium enolate of tert-butyl carboxylates, amides, lithium α-sulfonyl carbanions, and lithium α-carbanion of acetonitrile gave adducts in high to quantitative yields. The adducts were treated with Grignard regents, such as i-PrMgCl and EtMgCl in toluene to afford 1-substituted cyclopentenes in good to high yields with one-carbon ring-expansion via 1,2-carbon–carbon (1,2-CC) insertion reaction of the generated magnesium carbenoid intermediates. The magnesium carbenoid 1,2-CC insertion was found to be highly stereospecific. When optically pure chloromethyl p-tolyl sulfoxide was used in this procedure, optically active 1-substituted cyclopentenes were obtained in high optical purity.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::a9174815b93870c547482a34ba6ce309 https://doi.org/10.1016/j.tet.2010.12.023 Zobrazit plný text záznamu Full Text from ScienceDirect