Initial formation of an olefin-copper(I) π-complex in conjugate addition of lithium dimethylcuprate to t-butyl cinnamate

Hallnemo, Gerd; Olsson, Thomas; Ullenius, Christina

doi:10.1016/0022-328x(84)80079-0

Cited by 39 publications

(16 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[42] (15) (XANES) investigation of a complex between a transcinnamate and Me 2 CuLi´LiI in THF indicated elongation of the C À Cu bond and increase of the coordination number of the copper atom. NMR spectroscopic studies on the organic part of the complexes by Ullenius and co-workers, [178] Krause et al, [179] and others [180] indicated loosening of the olefinic bond. Very recently, Krause et al determined, for the first time, the kinetic activation energies (E a 17 ± 18 kcal mol À1 ) of some conjugate addition reactions.…”

Section: Kinetics and The Spectroscopic Analysis Of Intermediatesmentioning

confidence: 99%

Wherefore Art Thou Copper? Structures and Reaction Mechanisms of Organocuprate Clusters in Organic Chemistry

Nakamura

Mori

2000

Angew. Chem. Int. Ed.

270

186

View full text Add to dashboard Cite

Organocopper reagents provide the most general synthetic tools in organic chemistry for nucleophilic delivery of hard carbanions to electrophilic carbon centers. A number of structural and mechanistic studies have been reported and have led to a wide variety of mechanistic proposals, some of which might even be contradictory to others. With the recent advent of physical and theoretical methodologies, the accumulated knowledge on organocopper chemistry is being put together into a few major mechanistic principles. This review will summarize first the general structural features of organocopper compounds and the previous mechanistic arguments, and then describe the most recent mechanistic pictures obtained through high‐level quantum mechanical calculations for three typical organocuprate reactions, carbocupration, conjugate addition, and SN2 alkylation. The unified view on the nucleophilic reactivities of metal organocuprate clusters thus obtained has indicated that organocuprate chemistry represents an intricate example of molecular recognition and supramolecular chemistry, which chemists have long exploited without knowing it. Reasoning about the uniqueness of the copper atom among neighboring metal elements in the periodic table will be presented.

show abstract

Section: Kinetics and The Spectroscopic Analysis Of Intermediatesmentioning

confidence: 99%

Wherefore Art Thou Copper? Structures and Reaction Mechanisms of Organocuprate Clusters in Organic Chemistry

Nakamura

Mori

2000

Angew. Chem. Int. Ed.

270

186

View full text Add to dashboard Cite

show abstract

“…Die genauen Strukturen der Intermediate lagen lange Zeit im Dunkeln, doch zumindest in den Grundzügen wurde dieses Schema durch später durchgeführte NMR-Untersuchungen und neuere Rechnungen gestützt. NMR-Untersuchungen des organischen Anteils der Komplexe durch Ullenius et al, [178] Krause et al [179] und andere [180] deuteten auf eine Lockerung der Olefinbindung hin. (14)].…”

Section: Kinetik Und Die Spektroskopische Analyse Von Intermediatenunclassified

Warum denn Kupfer? – Strukturen und Reaktionsmechanismen von Organocupratclustern in der Organischen Chemie

Nakamura

Mori

2000

Angewandte Chemie

View full text Add to dashboard Cite

Organokupferreagentien sind in der Organischen Chemie die universellsten Synthesewerkzeuge für die nucleophile Übertragung harter Carbanionen auf elektrophile Kohlenstoffzentren. Es wurden schon viele Untersuchungen zu ihren Strukturen und Reaktionsmechanismen beschrieben; diese führten zu einem breiten Spektrum an Vorschlägen hinsichtlich des Mechanismus, die einander allerdings teilweise sogar widersprachen. Neuere theoretische und physikalische Methoden haben es möglich gemacht, aus dem gesammelten Wissen über die Organokupferchemie einige wenige mechanistische Grundprinzipien herauszuarbeiten. In diesem Beitrag wird zunächst ein Überblick über die allgemeinen Strukturmerkmale von Organokupferverbindungen und die früheren mechanistischen Überlegungen gegeben; anschließend werden die aktuellsten Vorstellungen präsentiert, die man durch quantenchemische Rechnungen auf hohem Niveau für drei typische Cupratreaktionen – die Carbocuprierung, die konjugierte Addition und die SN2‐Alkylierung – erhalten hat. Die so erlangte einheitliche Sicht der nucleophilen Reaktivität von Organocupratclustern enthüllte, dass die Organocupratchemie ein kompliziertes Beispiel für molekulare Erkennung und supramolekulare Chemie ist, das Chemiker seit langer Zeit nutzen, ohne dies geahnt zu haben. Wir werden auch eine Erklärung dafür liefern, warum das Kupferatom unter den benachbarten Elementen im Periodensystem so einzigartig ist.

show abstract

“…Copper-free PHM is catalytically inactive 53,62,78 . Cinnamates are known to form complexes with both Cu(I) 79,80 and Cu(II) 81 and copper removal/chelation has been attributed to specific PHM 61 and DβM inhibitors 68 . PHM inactivation requires turnover; thus, inactivation of PHM by cinnamate could result from the formation of a relatively high affinity cinnamate–Cu(I) complex.…”

Section: Discussionmentioning

confidence: 99%

Inactivation of peptidylglycineα-hydroxylating monooxygenase by cinnamic acid analogs

McIntyre

Lowe

Battistini

et al. 2015

Journal of Enzyme Inhibition and Medicinal Chemistry

View full text Add to dashboard Cite

Peptidylglycine α-amidating monooxygenase (PAM) is a bifunctional enzyme that catalyzes the final reaction in the maturation of α-amidated peptide hormones. Peptidylglycine α-hydroxylating monooxygenase (PHM) is the PAM domain responsible for the copper-, ascorbate- and O2-dependent hydroxylation of a glycine-extended peptide. Peptidylamidoglycolate lyase is the PAM domain responsible for the Zn(II)-dependent dealkylation of the α-hydroxyglycine-containing precursor to the final α-amidated peptide. We report herein that cinnamic acid and cinnamic acid analogs are inhibitors or inactivators of PHM. The inactivation chemistry exhibited by the cinnamates exhibits all the attributes of a suicide-substrate. However, we find no evidence for the formation of an irreversible linkage between cinnamate and PHM in the inactivated enzyme. Our data support the reversible formation of a Michael adduct between an active site nucleophile and cinnamate that leads to inactive enzyme. Our data are of significance given that cinnamates are found in foods, perfumes, cosmetics and pharmaceuticals.

show abstract

Initial formation of an olefin-copper(I) π-complex in conjugate addition of lithium dimethylcuprate to t-butyl cinnamate

Cited by 39 publications

References 5 publications

Wherefore Art Thou Copper? Structures and Reaction Mechanisms of Organocuprate Clusters in Organic Chemistry

Wherefore Art Thou Copper? Structures and Reaction Mechanisms of Organocuprate Clusters in Organic Chemistry

Warum denn Kupfer? – Strukturen und Reaktionsmechanismen von Organocupratclustern in der Organischen Chemie

Inactivation of peptidylglycineα-hydroxylating monooxygenase by cinnamic acid analogs

Contact Info

Product

Resources

About