Enantioselective synthesis of indole-fused dihydropyranones via catalytic cycloaddition of ketenes and 3-alkylenyloxindoles.
Chiral N-heterocyclic carbenes were found to be efficient catalysts for the formal [4+2] cycloaddition reaction of alkyl(aryl)ketenes and 3-alkylenyloxindoles to give the corresponding 3,4-dihydropyrano[2,3-b]indol-2-ones in excellent yields with good diastereo- and enantioselectivities.
Lv
Hui
H
CAS Key Laboratory of Molecular Recognition and Function, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Chen
Xiang-Yu
XY
Sun
Li-Hui
LH
Ye
Song
S
D002384:Catalysis; D003500:Cyclization; D005030:Ethylenes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D005030:Ethylenes; D007211:Indoles; D007659:Ketones; D011753:Pyrones; C008223:ketene