A new strategy, a transient homocoupling dimer strategy, for direct catalytic oxidative cross-enolate coupling reactions is developed. Cross-enolate coupling products bearing a (contiguous) tetrasubstituted carbon center were obtained chemoselectively without the need for stoichiometric amounts of strong bases/metal oxidants, and thus, the present catalysis provides a general method for the synthesis
Syn‐gled out: The syn diastereo‐ and enantioselective addition of azlactones to 3‐vinylindoles was accomplished by using a chiral, binapthol‐derived, Brønstedacid catalyst (see scheme). This method enables facileaccess to tryptophanderivatives with adjacent quaternary and tertiary stereogenic centers, which are potentially useful for the synthesis of peptidomimetics.
Organoselenium-Catalyzed Cross-Dehydrogenative Coupling of Alkenes and Azlactones
作者:Wei Wei、Xiaodan Zhao
DOI:10.1021/acs.orglett.2c00117
日期:2022.3.11
The carbon–carbonbond-formingcross-dehydrogenativecoupling of alkenes and azlactones by organoselenium catalysis involving a high-valent para-methoxyphenyl selenium species is disclosed. A series of α,α-disubstituted α-amino acid derivatives were obtained in excellent regioselectivities through vinyl or allylic C–H functionalization. The generality of the method was elucidated by the cross-coupling
Reported herein is a highly selective radical cascade-cross-coupling reaction for the modular synthesis of α-tertiary aminoacids (ATAA) under mild conditions. Mechanistic studies reveal the excited state of an in situ-generated oxazolone enolate as a key intermediate, which functions both as a radical precursor and an efficient reductant.
α-Quaternary amino acids have found application in many biologically relevant compounds and pharmaceuticals. Although there are many methods for the synthesis of α-quaternary amino acids, most of them are mainly realized with the aid of transition metals and complex ligands. We present herein a 2,7-Br-4CzIPN catalyzed regioselective alkylation of azlactones with redox-active esters via radical–radical