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Iodoindazoles with Selective Magnesiation at Position 3: A Route to Highly Functionalized Indazoles
Author(s) -
Lam Bao Vy,
Berhault Yohann,
Stiebing Silvia,
Fossey Christine,
Cailly Thomas,
Collot Valérie,
Fabis Frédéric
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201504828
Subject(s) - halogen , electrophile , regioselectivity , combinatorial chemistry , chemistry , iodine , position (finance) , organic chemistry , catalysis , alkyl , finance , economics
A unique route to highly functionalized indazoles is described. A regioselective magnesiation at position 3 of 4‐, 5‐, 6‐ and 7‐iodo‐2‐THP‐indazoles (THP=tetrahydropyranyl) has been developed using TMPMgCl ⋅ LiCl (TMP=2,2,6,6‐tetramethylpiperidyl). The obtained magnesiate can be trapped by different electrophiles to introduce a wide range of functional groups including halogens, thioalkyls, alcohols, aldehydes, ketones, amides, or esters at position 3. Once this position is functionalized, the iodine atoms can be further reacted through metal–halogen exchange or cross‐coupling strategies. Finally, N‐substitution reactions allow the synthesis of a variety of highly functionalized indazoles giving access to these valuable scaffolds through a simple and unique route.