54716-19-7Relevant academic research and scientific papers
Palladium-Catalyzed Aminocarbonylation of Allylic Alcohols
Li, Haoquan,Neumann, Helfried,Beller, Matthias
supporting information, p. 10050 - 10056 (2016/07/19)
A benign and efficient palladium-catalyzed aminocarbonylation reaction of allylic alcohols is presented. The generality of this novel process is demonstrated by the synthesis of β,γ-unsaturated amides including aliphatic, cinnamyl, and terpene derivatives. The choice of ligand is crucial for optimal carbonylation processes: Whereas in most cases the combination of PdCl2with Xantphos (L6) gave best results, sterically hindered substrates performed better in the presence of simple triphenylphosphine (L10), and primary anilines gave the best results using cataCXium PCy (L8). The reactivity of the respective catalyst system is significantly enhanced by addition of small amounts of water. Mechanistic studies and control experiments revealed a tandem allylic alcohol amination/C?N bond carbonylation reaction sequence.
Pd-catalyzed carbonylation of diazo compounds at atmospheric pressure: A catalytic approach to ketenes
Zhang, Zhenhua,Liu, Yiyang,Ling, Lin,Li, Yuxue,Dong, Yian,Gong, Mingxing,Zhao, Xiaokun,Zhang, Yan,Wang, Jianbo
supporting information; experimental part, p. 4330 - 4341 (2011/06/21)
The carbonylation of carbenes through catalytic cycles is highly desirable due to the importance of ketene-mediated reactions in organic synthesis. In this investigation, a highly efficient and mild catalytic approach toward ketene intermediates has been developed based on Pd-catalyzed carbonylation of diazo compounds with CO. When α-diazocarbonyl compounds or N-tosylhydrazone salts are heated in the presence of a palladium catalyst under atmospheric pressure of CO, ketene intermediates are formed in situ, where they undergo further reactions with various nucleophiles such as alcohols, amines, or imines. The Pd-catalyzed tandem carbonylation-Staudinger cycloaddition gives β-lactam derivatives in good yields with excellent trans diastereoselectivity. The results from DFT calculation on the reaction mechanism suggest that Pd is involved in the [2 + 2] cycloaddition process and affects the diastereoselectivity of the β-lactam products by assisting isomerization of the addition intermediate. On the other hand, the acylketenes generated from the Pd-catalyzed carbonylation of α-diazoketones react with imines in a formal [4 + 2] cycloaddition manner to afford 1,3-dioxin-4-one derivatives. This straightforward carbonylation provides a new approach toward highly efficient catalytic generation of ketene species under mild conditions.
STOECHIOMETRISCHE UND KATALYTISCHE CC-VERKNUEPFUNGEN ZWISCHEN 1,3-BUTADIEN UND PHENYLISOCYANAT AN NICKEL(0)-KOMPLEXEN
Hernandez, Elisa,Hoberg, Heinz
, p. 429 - 436 (2007/10/02)
The CC coupling of 1,3-butadiene with phenylisocyanate at nickel(0) systems is ligand-dependent.Basic phosphanes such as triethyl- or tricyclohexylphosphane induce a stoichiometric 1/1 CC-coupling reaction yielding azanickela complexes.Triphenylphosphane, on the other hand, leads to a catalytic reaction.Catalysis is initiated by 2/1 coupling, which, after intramolecular cyclisation finally yields carbocyclic five-ring amides.Some special features are listed and the reaction mechanisms are discussed.
