Palladium-catalysed diastereodivergent inverse-electron-demand oxa-Diels–Alder reactions of in situ formed cyclopentadienones via ligand-control

Abstract

Here we report Pd(0)-catalysed asymmetric inverse-electron-demand oxa-Diels-Alder reactions between the carbonates of 4-hydroxy-2-cyclopentenones and α-cyano chalcones, by in situ generating η2-Pd(0)-cyclopentadienone complexes as HOMO-raised dienophiles, and diastereodivergent synthesis could be...

A metal π-Lewis base activation model for Pd-catalyzed hydroamination of amines and 1,3-dienes

“… 6 Our previous work indicated that the highest occupied molecular orbital (HOMO) energy of a η 2 -coordinated Pd(0)-diene complex is significantly raised compared with the parent one. 7 It directly enhances the nucleophilicity of 1,3-dienes to attack electrophilic partners in a Friedel–Crafts reaction pattern ( Scheme 1b ). As a result, we speculated that a π-Lewis base activation mode might be similarly involved in the reported Pd-catalyzed hydroamination of 1,3-dienes ( Scheme 1c ).…”

Pd-catalyzed Stereodivergent [4+2] Annulation to Access [6.7]-Fused N-Heterocycles

“…Although very recently stereodivergent annulations by using different palladium zwitterionic π-allyl intermediates with the solely Pd catalysis have made progress by the groups of Trost et al 12 , You et al 13 , Chen et al 14 and Lee et al 15 as shown in Scheme 1D. The efficiency and diastereodivergency of these reactions were still lower than desired, and the product types were largely limited to simple carbon and oxygen-containing ring systems.…”

Palladium-catalyzed Lewis acid-regulated cascade annulation of alkynes with unactivated alkenes to access diverse α-methylene-γ-lactones

“…2 Particularly, transition metal-catalyzed protocols have been recognized as one of the most reliable and straightforward strategies to fulfil this selectivity. Among them, catalyst-controlled, 3 ligand-controlled, 4 solvent-dependent, 5 and substrate-induced 6 selective divergent synthesis have also provided an indispensable avenue for the assembly of diversified functional molecules. It is noteworthy that Lewis acid-regulated catalytic methodologies have been widely employed as the guiding tactic for the construction of complex molecular frameworks with highly regio- and stereoselectivity in recent years.…”