Regioselective Synthesis of 1,3,4,5-Tetrasubstituted Pyrazoles from α-Alkenyl-α,β-Enones Derived from Morita-Baylis-Hillman Adducts
作者:Sung Hwan Kim、Jin Woo Lim、Jin Yu、Jae Nyoung Kim
DOI:10.5012/bkcs.2013.34.10.2915
日期:2013.10.20
Convenient synthetic method for 4-arylethylpyrazoles and 4-styrylpyrazoles was developed using $\alpha}$-alkenyl-$\alpha},\beta}$-enones readily accessed from the Morita-Baylis-Hillman reaction. For the synthesis of 4-arylethylpyrazole, the reactions with arylhydrazines needed to be carried out in o-dichlorobenzene under $N_2$ balloon atmosphere. On the other hand, 4-styrylpyrazoles required the reactions in ethanol under $O_2$ balloon atmosphere.
The highly stereoselective allylicalkylation of Morita–Baylis–Hillman carbonates with β-ketoesters catalysed by β-ICD is described. The corresponding products containing two adjacent quaternary and tertiary carbon centers were obtained in good yields with high diastereoselectivity (up to 10 : 1 dr) and enantioselectivity (up to 95% ee).
The coupling of α,β-unsaturated carbonyl compounds with aldehydes (the Baylis-Hillman reaction) was accelerated in the presence of a catalytic amount of 1,4-diazabicyclo[2,2,2]octane (DABCO) and lithium perchlorate in ether. A preliminary kinetic study revealed that the relative rate of the reaction using LiClO4 in ether was 8.0×102 times faster than that of the reaction without LiClO4.
DMAP-Catalyzed [3 + 2] and [4 + 2] Cycloaddition Reactions between [60]Fullerene and Unmodified Morita–Baylis–Hillman Adducts in the Presence of Ac<sub>2</sub>O
作者:Hai-Tao Yang、Wen-Long Ren、Chun-Bao Miao、Chun-Ping Dong、Yang Yang、Hai-Tao Xi、Qi Meng、Yan Jiang、Xiao-Qiang Sun
DOI:10.1021/jo3025797
日期:2013.2.1
One-step DMAP-catalyzed [3 + 2] and [4 + 2] cycloaddition reactions between C60 and unmodified Morita–Baylis–Hillman adducts in the presence of Ac2O have been developed for the easy preparation of cyclopentene- and cyclohexene-fused [60]fullerene derivatives. When the MBH adducts bear an alkyl group, two different reaction pathways could be controlled selectively depending on the conditions.
Bifunctional Polymeric Organocatalysts and Their Application in the Cooperative Catalysis of Morita–Baylis–Hillman Reactions
作者:Cathy Kar-Wing Kwong、Rui Huang、Minjuan Zhang、Min Shi、Patrick H. Toy
DOI:10.1002/chem.200601197
日期:2007.3.5
these polymeric reagents contained either alkyl alcohol or phenol groups on the polymer backbone. The use of these materials as organocatalysts in a range of Morita-Baylis-Hillman reactions indicated that hydroxyl groups could participate in the reactions and accelerate product formation. In the cases examined, phenol groups were more effective than alkyl alcohol groups for catalyzing the reactions