Deproto-metallation using a mixed lithium-zinc base and computed CH acidity of 1-aryl 1H-benzotriazoles and 1-aryl 1H-indazoles.
1-Aryl-1H-benzotriazoles and -1H-indazoles were synthesized, and their deproto-metallation using the base prepared by mixing LiTMP with ZnCl2·TMEDA (1/3 equiv.) was studied. In the indazole series, reactions occurring at the 3 position were followed by ring opening, and functionalization of the substrate was only found possible (on the sulfur ring) using 2-thienyl as aryl group. In the benzotriazole series, either mono- or bis-deprotonation (depending on the amount of base employed) was achieved with phenyl, 4-methoxyphenyl and 2-thienyl as aryl group, and bis-deprotonation in the case of 4-chlorophenyl and 4-trifluoromethylphenyl. The experimental results were analyzed with the help of the CH acidities of the substrates, determined in THF solution using the DFT B3LYP method.
Equipe Chimie et Photonique Moléculaires, Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Bâtiment 10A, Case 1003, Campus Scientifique de Beaulieu, 35042 Rennes, France. floris.chevallier@univ-rennes1.fr florence.mongin@univ-rennes1.fr.
Elisabeth
E
Nagaradja
Floris
F
Chevallier
Thierry
T
Roisnel
Vincent
V
Dorcet
Yury S
YS
Halauko
Oleg A
OA
Ivashkevich
Vadim E
VE
Matulis
Florence
F
Mongin
D007191:Indazoles / Q000138:chemical synthesis* / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011789:Quantum Theory; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
D007191:Indazoles; D009942:Organometallic Compounds; D014230:Triazoles; C012771:benzotriazole; D008094:Lithium; D015032:Zinc