Synthesis of Cyclopentenols and Cyclopentenones via Nickel-Catalyzed Reductive Cycloaddition
作者:Aireal D. Jenkins、Ananda Herath、Minsoo Song、John Montgomery
DOI:10.1021/ja206722t
日期:2011.9.14
Strategies for the reductive cycloaddition of enals or enoates with alkynes have been developed. The enal-alkyne cycloaddition directly affords cyclopentenols, whereas the enoate-alkyne cycloaddition affords the analogous cyclopentenones. The mechanism of these processes likely involves formation and protonation of a metallacyclic intermediate. The general strategy provides a straightforward entry
Structure of an η<sup>1</sup> Nickel <i>O</i>-Enolate: Mechanistic Implications in Catalytic Enyne Cyclizations
作者:Kande K. D. Amarasinghe、Sanjoy K. Chowdhury、Mary Jane Heeg、John Montgomery
DOI:10.1021/om0010013
日期:2001.2.1
Two metallacycles derived from the oxidative cyclization of nickel(0) with an alkynyl enal have been isolated and fully characterized. The metallacycles obtained possess an η1nickelO-enolate motif within the metallacyclic framework.
Cascade Cyclizations and Couplings Involving Nickel Enolates
作者:Gireesh M. Mahandru、Andy R. L. Skauge、Sanjoy K. Chowdhury、Kande K. D. Amarasinghe、Mary Jane Heeg、John Montgomery
DOI:10.1021/ja037423w
日期:2003.11.1
A new strategy for effecting cascade cyclization processes using nickel enolates has been developed. Nickel enolates may be cleanly generated by the oxidative cyclization of an enal and alkyne with Ni(0), and the resulting enolate may be functionalized by a variety of alkylation processes. Partially and fully intramolecular versions of the process allow the rapid synthesis of complex polycyclics from simple achiral, acyclic precursors.
Diverse Reactivity Manifolds of Alkynyl Enone- and Alkynyl Enal-Derived Nickelacycles: Discovery of Nickel-Promoted [3+2] and [2+1] Cycloadditions
作者:Sanjoy K. Chowdhury、Kande K. D. Amarasinghe、Mary Jane Heeg、John Montgomery
DOI:10.1021/ja0012624
日期:2000.7.1
Counteranion-controlled regioselectivity in palladium-catalyzed allylic amination of dienyl allylic carbonates
作者:Meng-Lan Shen、Pu-Sheng Wang、Liu-Zhu Gong
DOI:10.1016/j.tet.2021.131996
日期:2021.3
A regioselective Pd-catalyzed allylic amination reaction of dienyl allylic carbonates and aromatic amines has been developed by means of phosphoramidte-palladium catalysis. The regioselectivity could be altered by the counterion of the π-allylpalladium intermediate. As a result, either branched Z-dienyl allylic amines or linear conjugated allylic amines were generated in high levels of regioselectivity