RT info:eu-repo/semantics/article
T1 Chiral Bifunctional Thioureas and Squaramides and Their Copolymers as Recoverable Organocatalysts. Stereoselective Synthesis of 2-Substituted 4-Amino-3-nitrobenzopyrans and 3-Functionalized 3,4-Diamino-4H-Chromenes
A1 Andrés García, José María
A1 Maestro Fernández, Alicia
A1 Valle Álvarez, María
A1 Pedrosa Sáez, Rafael
K1 Aminobenzopiranos
K1 Aminobenzopyranes
AB Novel styryl-substituted thioureas and squaramides were obtained in three steps from commercially available 4-hydroxy-3,5-dichloroaniline. These organocatalysts promote cascade reactions in high yields and excellent stereoselection. By using only a 5 mol % loading of catalyst, it is possible to obtain 2,3,4-trisubstituted benzopyrans by reaction of α-amido sulfones derived from salicyladehydes and nitrostyrenes or 2,3,4-trisubstituted 4H-chromenes by reaction of the same α-amido sulfones with (phenylsulfonyl)acetonitrile in excellent diastereo- and enantioselectivities. Two polymeric thioureas and squaramides were prepared by copolymerization of the best monomeric catalysts with styrene and divinylbenzene and used for the same transformations. These polymers behave also as excellent stereoselective catalysts that can be recovered and reused for five cycles.
PB American Chemical Society
SN 0022-3263
YR 2018
FD 2018
LK http://uvadoc.uva.es/handle/10324/32370
UL http://uvadoc.uva.es/handle/10324/32370
LA eng
NO Journal of Organic Chemistry, 2018, 83 (10), pp 5546–5557
NO Producción Científica
DS UVaDOC
RD 29-abr-2024