Heteroatom-guided torquoselective olefination of alpha-oxy and alpha-amino ketones via ynolates.
Ynolates were found to react with alpha-alkoxy-, alpha-siloxy-, and alpha-aryloxyketones at room temperature to afford tetrasubstituted olefins with high Z selectivity. Since the geometrical selectivity was determined in the ring opening of the beta-lactone enolate intermediates, the torquoselectivity was controlled by the ethereal oxygen atoms. From experimental and theoretical studies, the high Z selectivity is induced by orbital and steric interactions rather than by chelation. In a similar manner, alpha-dialkylamino ketones provided olefins with excellent Z selectivity. These products can be easily converted into multisubstituted butenolides and gamma-butyrolactams in good yield.
Shindo
Mitsuru
M
Institute for Materials Chemistry and Engineering, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580, Japan. shindo@cm.kyushu-u.ac.jp
Yoshikawa
Takashi
T
Itou
Yasuaki
Y
Mori
Seiji
S
Nishii
Takeshi
T
Shishido
Kozo
K
D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000138:chemical synthesis; D000475:Alkenes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods*; D007659:Ketones / Q000737:chemistry*
D000475:Alkenes; D000588:Amines; D007659:Ketones; C004511:butenolide; D015107:4-Butyrolactone