Toward a better understanding on the mechanism of ortholithiation. Tuning of selectivities in the metalation of meta-anisic acid by an appropriate choice of base.
[reaction: see text] If employed in THF at 0 degrees C, LTMP metalates meta-anisic acid at the doubly activated position. In contrast, n-BuLi/t-BuOK deprotonates position C-4 preferentially at low temperature. Functionalization at C-6 requires protection of the C-2 site beforehand. As a result of these findings, a new mechanism is proposed for the heteroatom-directed ortholithiation of aromatic compounds.
Nguyen
Thi-Huu
TH
Unité de Chimie Organique Moléculaire et Macromoléculaire (UMR 6011), Faculté des Sciences, Université du Maine and CNRS, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France.
Chau
Nguyet Trang Thanh
NT
Castanet
Anne-Sophie
AS
Nguyen
Kim Phi Phung
KP
Mortier
Jacques
J
D002625:Chemistry, Organic / Q000379:methods; D008094:Lithium / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature; D013816:Thermodynamics; D014641:Vanillic Acid / Q000031:analogs & derivatives* / Q000737:chemistry
D009942:Organometallic Compounds; D008094:Lithium; C056267:3-methoxybenzoic acid; D014641:Vanillic Acid