31021-02-0Relevant articles and documents
Activated charcoal-mediated synthesis of chalcones catalyzed by NaOH in water
Tanemura, Kiyoshi,Rohand, Taoufik
, (2021/02/27)
A variety of chalcones were synthesized in good yields by the activated charcoal-mediated aldol reactions between benzaldehydes and acetophenones catalyzed by NaOH in water. 2,6-Bis((E)-benzylidene)cyclohexan-1-ones were prepared by the aldol reactions between benzaldehydes and cyclohexanone. Activated charcoal could be recycled five times without the significant decrease of yields.
Redox-Neutral Cobalt(III)-Catalyzed C-H Activation/Annulation of α,β-Unsaturated Oxime Ether with Alkyne: One-Step Access to Multisubstituted Pyridine
Mohanty, Smruti Ranjan,Pati, Bedadyuti Vedvyas,Banjare, Shyam Kumar,Das Adhikari, Gopal Krushna,Ravikumar, Ponneri Chandrababu
, p. 1074 - 1083 (2021/01/14)
A redox neutral Co(III)-catalyzed annulation of α,β-unsaturated oxime ether with alkyne has been reported. Multisubstituted pyridines were synthesized in good yields without the use of any heavy metal oxidants. The developed methodology tolerates a variety of functional groups. Notably, this transformation has been applied to the late-stage modification of the bioactive molecule dehydropregnenolone.
Rhodium-catalyzed asymmetric hydrogenation of exocyclic α,β-unsaturated carbonyl compounds
Yang, Jiaxin,Li, Xiuxiu,You, Cai,Li, Shuailong,Guan, Yu-Qing,Lv, Hui,Zhang, Xumu
supporting information, p. 856 - 859 (2020/02/15)
A highly enantioselective hydrogenation of exocyclic α,β-unsaturated carbonyl compounds catalyzed by Rh/bisphosphine-thiourea (ZhaoPhos) has been developed, giving the corresponding α-chiral cyclic lactones, lactams and ketones with high yields and excellent enantioselectivities (up to 99% yield and 99% ee). Remarkably, the hydrogen bond between the substrate and the catalyst plays a critical role in this transformation. The synthetic utility of this protocol has been demonstrated by efficient synthesis of chiral 3-(4-fluorobenzyl)piperidine, a key chiral fragment of bioactive molecules.