138190-35-9Relevant academic research and scientific papers
Reactivity of (Z)-4-Aryliden-5(4 H)-thiazolones: [2 + 2]-Photocycloaddition, Ring-Opening Reactions, and Influence of the Lewis Acid BF3
Sierra, Sonia,Dalmau, David,Higuera, Sheila,Cortés, Darío,Crespo, Olga,Jimenez, Ana I.,Pop, Alexandra,Silvestru, Cristian,Urriolabeitia, Esteban P.
, p. 12119 - 12140 (2021)
The irradiation of (Z)-2-phenyl-4-aryliden-5(4H)-thiazolones 2 with blue light (465 nm) in CH2Cl2 solution promotes [2 + 2]-photocycloaddition of the exocyclic C═C bonds and the formation of the dispirocyclobutanes 3. This reaction takes place with high stereoselectivity, given that the ?-isomer (1,3 head-to-tail syn coupling) is formed in more than 90% yield in most of the cases. However, irradiation of 5(4H)-thiazolones 2 with blue light (456 nm) in dry MeOH in the presence of BF3·OEt2 leads to the monospirocyclobutanes 4 with full stereoselectivity, also affording the ?-isomer. A ring-opening reaction of only one of the thiazolone rings appears to have taken place in 4 upon methanolysis, leading to the corresponding ester and thioamide groups. The treatment of free 4-aryliden-5(4H)-thiazolones 2 with a base in alcohol (NaOR/ROH) also produces a ring-opening reaction of the heterocycle by methanolysis, although, under these reaction conditions, further intramolecular S-attack at the exocyclic C(H)═C bond and cyclization is observed, forming the dihydrothiazoles 5 or 6 as mixtures of cis (RS/SR)- and trans (RR/SS)-isomers with high diastereomeric excess. trans-(RR/SS)-Dihydrothiazoles 6 can be isolated as pure diastereoisomers by column chromatography. Surprisingly, dihydrothiazoles 5 can also be obtained by the treatment of 4-aryliden-5(4H)-thiazolones 2 with BF3·OEt2 in methanol in the absence of a base.
Improved erlenmeyer synthesis with 5-thiazolone and catalytic Mn(II) acetate. Crystal structure confirmation of the reaction stereochemistry
Chandrasekhar, Sosale,Mohana Rao
, p. E172-E175 (2014)
2-Phenylthiazolin-5-one (5, a thioazlactone) condenses with various aldehydes in the presence of the mild base Mn(II) acetate as catalyst in CH 2Cl2 solution. This leads to the corresponding Erlenmeyer reaction products (6) in excell
