71711-98-3Relevant articles and documents
Vinylogous Aza-Michael Addition of Urea Derivatives with p-Quinone Methides Followed by Oxidative Dearomative Cyclization: Approach to Spiroimidazolidinone Derivatives
Kaur, Navpreet,Singh, Priyanka,Banerjee, Prabal
supporting information, p. 2813 - 2824 (2021/04/21)
Herein, we report an efficient protocol for the synthesis of spiro-imidazolidinone-cyclohexadienones from p-quinone methides (p-QMs) and dialkyloxy ureas under mild conditions. The strategy follows a two-step process involving an initial vinylogous conjugate addition of urea derivatives to p-QMs, followed by oxidative dearomative cyclization of open-chain product to the projected spiro-imidazolidinones. This protocol exhibits good functional group tolerance and provides a straightforward method to access spiro-imidazolidinone-cyclohexadienones. In follow-up chemistry, we have shown the debenzylation of spiroimidazolidinones to give N-hydroxycyclic ureas. (Figure presented.).
Thiourea catalyzed 1,6-conjugate addition of indoles to para-quinone methides
Wu, Guangmiao,Li, Tao,Liu, Fuhai,Zhao, Yulong,Ma, Shiqiang,Tang, Shouchu,Xie, Xingang,She, Xuegong
supporting information, (2021/09/09)
An efficient thiourea catalyzed 1,6-conjugate addition of indoles to para-quinone methides (p-QMs) was developed. p-QMs was activated by a weak hydrogen-bond effect. The reaction is featured mild reaction conditions and wide substrate scope. A series of C-3 bisaryl methine substituted indoles are prepared in high yield.
Organocatalytic Enantioselective 1,6-aza-Michael Addition of Isoxazolin-5-ones to p-Quinone Methides
Torán, Ricardo,Vila, Carlos,Sanz-Marco, Amparo,Mu?oz, M. Carmen,Pedro, José R.,Blay, Gonzalo
supporting information, p. 627 - 630 (2020/02/05)
A thiourea-Br?nsted base bifunctional catalyst allowed the enantioselective 1,6-aza-Michael addition of isoxazolin-5-ones to p-quinone methides to give isoxazolin-5-ones having a chiral diarylmethyl moiety attached to the N atom with fair to good yields and enantiomeric excesses. To the best of our knowledge this reaction represents the first example of enantioselective N-alkylation of isoxazolin-5-ones as well as the first example of enantioselective 1,6-aza-Michael reaction involving p-quinone methides.