Asymmetric C2-C3 cyclopentannulation of the indole ring.
Chiral nonracemic alkynyl(alkoxy)carbene complexes of tungsten(0) undergo the [3 + 2] cyclization toward alpha-methylindoles and 1,6-dimethyl-1,2,3,4-tetrahydropyridine to provide 2,3-indoline-fused cyclopentenone and 2,3-piperidine-fused cyclopentenone skeletons, respectively, with very high enantiomeric purities (96-99% ee).
Barluenga
José
J
Instituto Universitario de Química Organometálica Enrique Moles, Unidad Asociada al C.S.I.C., Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
Tudela
Eva
E
Ballesteros
Alfredo
A
Tomás
Miguel
M
D000480:Alkynes / Q000737:chemistry*; D003517:Cyclopentanes / Q000138:chemical synthesis*; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D010880:Piperidines / Q000138:chemical synthesis*; D011725:Pyridines / Q000737:chemistry*; D013237:Stereoisomerism; D014414:Tungsten / Q000737:chemistry
D000480:Alkynes; D003517:Cyclopentanes; D007211:Indoles; D010880:Piperidines; D011725:Pyridines; C057812:indoline; C013905:cyclopentenone; D014414:Tungsten