Synthesis of Tetrahydropyridines from Morita–Baylis–Hillman Acetates of α,β‐Unsaturated Aldehydes Via an Intramolecular 1,6‐Conjugate Addition

The Tungsten-Promoted Synthesis of Piperidyl-Modified erythro-Methylphenidate Derivatives

“…2D NMR analysis indicated that this compound was likely a constitutional isomer of THP 21-Ms in which the alkene has migrated to form the “enamide” 21′ (Figure ). Similar palladium-catalyzed isomerizations have been reported for other THPs and for a 3-pyrrolene, in which an enamide (2-pyrrolene) was formed. − As anticipated, further reduction of the mixture of 26 and 21′ resulted in complete conversion to the piperidine 26 . The structure of 26 was confirmed via SC-XRD.…”

Et3B-mediated and palladium-catalyzed direct allylation of β-dicarbonyl compounds with Morita–Baylis–Hillman alcohols

“…We believe that the treatment of the MBH alcohol 1a with Et 3 B in the presence of Pd(OAc) 2 may generate a π-allylpalladium intermediate I that further undergoes a nucleophilic substitution reaction with the β-keto ester carbanion derived from 2j , affording the monoallylated compound 3j . The conversion of the keto ester 3j into the tricyclic product 6j was further performed through an intramolecular conjugate addition of the β-keto ester carbanion onto the enone moiety (Scheme 2) [50–51]. …”

Palladium‐Catalyzed Aminomethylation of Nitrodienes and Dienones via Double C—N Bond Activation

“…The dienyl allylic amines and their derivatives are not only important building blocks for the synthesis of various nitrogen‐ containing compounds, but also widely found in natural products as well as biologically active molecules. [ 1‐6 ] It is a surprise to find that the catalytic reactions for constructing such a kind of scaffolds remain largely undeveloped, and only few Ir‐catalyzed allylic aminations of dienyl allylic carbonates or alcohols have been reported. [ 7‐8 ] On the other hand, the reaction of activated functionalized dienes with imines or iminium salts under the Morita‐Baylis‐ Hillman (MBH) conditions is another promising approach to functionalized dienyl allylic amines.…”