7788-69-4Relevant articles and documents
Direct Formation of 2-Substituted 2 H-Indazoles by a Pd-Catalyzed Reaction between 2-Halobenzyl Halides and Arylhydrazines
Aljaar, Nayyef,Al-Noaimi, Mousa,Conrad, Jürgen,Beifuss, Uwe
, p. 1408 - 1418 (2021/01/14)
A direct and operationally simple method for the regioselective synthesis of 2-aryl-substituted 2H-indazoles is reported. The Pd-catalyzed reaction between easily available 2-bromobenzyl bromides and arylhydrazines employing Cs2CO3 as the base and t-Bu3PHBF4 as the ligand in DMSO at 120 °C in a sealed tube delivers the 2-substituted-2H-indazoles in a single synthetic step with yields up to 79%. The new method is based on a regioselective intermolecular N-benzylation followed by intramolecular N-arylation and oxidation.
Cu(I)–N-heterocyclic carbene-catalyzed base free C–N bond formation of arylboronic acids with amines and azoles
Zhang, Maoyuan,Xu, Zengbing,Shi, Dabin
, (2020/12/25)
A new N-heterocyclic carbene (NHC) precursor of imidazolium chloride and its corresponding Cu(I)–NHC complex 1 was synthesized. The complex 1 was found to be a highly effective catalyst for Chan-Evans-Lam coupling of arylboronic acid with amines and azoles (including imidazole, pyrazole and triazole), without addition of base at room temperature. Various substituents on three substrates can be tolerated, giving the desired coupling products in good to excellent yields (62–94%). The method is practical and offers an alternative to the corresponding copper-catalyzed Chan-Evans-Lam process for the construction of C–N bonds.
“On Water” Palladium Catalyzed Direct Arylation of 1H‐Indazole and 1H‐7‐Azaindazole
Abbouchi, Abdelmoula El,Akssira, Mohamed,Bousmina, Mostapha,El Kazzouli, Sa?d,Gambouz, Khadija,Guillaumet, Gérald,Nassiri, Sarah,Suzenet, Franck
, (2020/07/02)
The C3 direct arylation of 1H-indazole and 1H-7-azaindazole has been a significant challenge due to the lack of the reactivity at this position. In this paper, we describe a mild and an efficient synthesis of new series of C3-aryled 1H-indazoles and C3-aryled 1H-7-azaindazoles via a C3 direct arylation using water as solvent. On water, PPh3 was effective as a ligand along with a lower charge of the catalyst Pd(OAc)2 (5 mol%) at 100 oC, leading to C3-aryled 1H-indazoles or C3-aryled 1H-7-azaindazoles in moderate to good yields.
