Fe(III)-Catalyzed Aerobic Intramolecular N–N Coupling of Aliphatic Azides with Amines
摘要:
An Fe(III)-catalyzed intramolecular N-N coupling of aliphatic azidoamines that forms diverse five-and six-membered semisaturated diazoheterocycles using air as an oxidant is reported, providing an alternative to hydrazine-based methods. Mechanistic studies suggest that a N-radical induced intramolecular homolytic substitution (S(H)2) is involved in ring closure. The power of this N-N bond-forming method is also demonstrated by using it as the final step in a total synthesis of (-)-newbouldine.
Compounds of the formula (I), in which R
1
, R
2
, R
3a
, R
3b
, R
3c
and R
3d
have the meanings indicated in claim
1
, are inhibitors of tyrosine kinases, in particular Met kinase, and can be employed, inter alia, for the treatment of tumours.
Ruthenium-Catalyzed Divergent Acceptorless Dehydrogenative Coupling of 1,3-Diols with Arylhydrazines: Synthesis of Pyrazoles and 2-Pyrazolines
作者:Yanling Zheng、Yang Long、Huihua Gong、Jiaqi Xu、Chunchun Zhang、Haiyan Fu、Xueli Zheng、Hua Chen、Ruixiang Li
DOI:10.1021/acs.orglett.2c01497
日期:2022.6.3
1,3-diols with arylhydrazines via acceptorless dehydrogenativecoupling reactions to selectively synthesize pyrazoles and 2-pyrazolines were reported, which were based on Ru3(CO)12/NHC-phosphine-phosphine catalytic systems. The reactions featured low catalyst loading, high selectivity, wide substrate scope, and good yields, with only water and hydrogen gas (H2) as the byproducts.