Synthesis of isothiosemicarbazones of potential antitumoral activity through a multicomponent reaction involving allylic bromides, carbonyl compounds and thiosemicarbazide
作者:Laiéli S. Munaretto、Misael Ferreira、Daniela P. Gouvêa、Adailton J. Bortoluzzi、Laura S. Assunção、Juliana Inaba、Tânia B. Creczynski-Pasa、Marcus M. Sá
DOI:10.1016/j.tet.2020.131231
日期:2020.6
of isothiosemicarbazones and 2-hydrazono-1,3-thiazin-4-ones through a multicomponent reaction featuring allylic bromides, carbonylcompounds and thiosemicarbazides is described. The transformations proceed under mild and environmentally benign conditions with high yields and stereoselectivity. All novel compounds were obtained in high purity without the need for chromatography stages. Different functional
Diastereoselective synthesis of α-(aminomethyl)-γ-butyrolactones via a catalyst-free aminolactonization
作者:P. Veeraraghavan Ramachandran、Daniel R. Nicponski
DOI:10.1039/c4cc05765a
日期:——
An auto-catalytic domino reaction involving an aza-Michael reaction, proton transfer, and lactonization furnishing α-aminomethyl-γ-butyrolactones in near quantitative yields and excellent diastereoselectivity is described.
Microwave-assisted synthesis of the (E)-α-methylalkenoate framework from multifunctionalized allylic phosphonium salts
作者:Lidiane Meier、Misael Ferreira、Marcus M. Sá
DOI:10.1002/hc.21001
日期:——
A convenient and general microwave-assisted method for the synthesis of stereochemicallydefined α-methylalkenoic acids and esters from allylic phosphonium salts in a basic aqueous medium is described. A selective preparation of acids or esters was dependent on the base (NaOH or NaHCO3) employed in the reaction and could be achieved with good to excellent yields under mild conditions in the absence
4-(Dimethylamino)pyridine as a catalyst for the lactonization of 4-hydroxy-2-methylenebutanoate esters
作者:Daniel R. Nicponski
DOI:10.1016/j.tetlet.2014.02.024
日期:2014.3
The catalytic action of 4-(dimethylamino)pyridine (DMAP) in lactonizing 4-hydroxy-2-methylenebutanoate esters to 2-methylene-γ-butyrolactones is described. The use of DMAP, which functions as an excellent complement to the more traditional acid-catalyzed lactonization protocol, allows for the synthesis of 2-methylene-γ-butyrolactones containing acid-sensitive groups under essentially neutral conditions
Palladium-Catalyzed Domino Cyclization (5-<i>exo</i>/3-<i>exo</i>), Ring- Expansion by Palladium Rearrangement, and Aromatization: An Expedient Synthesis of 4-Arylnicotinates from Morita-Baylis-Hillman Adducts
作者:Ko Hoon Kim、Se Hee Kim、Hyun Ju Lee、Jae Nyoung Kim
DOI:10.1002/adsc.201300211
日期:2013.7.8
Various 4‐arylnicotinate derivatives were synthesized via a palladium‐catalyzed cascade reaction of N‐(2‐bromoallyl)‐N‐cinnamyltosylamides in a one‐pot procedure in good yields. The reaction involves a domino 5‐exo/3‐exo carbopalladation, ring‐expansion by palladiumrearrangement, and an aromatization process.