Nickel‐Catalyzed CO₂ Rearrangement of Enol Metal Carbonates for the Efficient Synthesis of β‐Ketocarboxylic Acids

Abstract

4-Methylene-1,3-dioxolan-2-ones underwent oxidative addition of aNi 0 catalyst in the presence of Me 2 Al(OMe), followed by ac oupling reaction with alkynes,t of orm d,eunsaturated b-ketocarboxylic acids with high regio-and stereoselectivity.The reaction proceeds by [1,3] rearrangement of an enol metal carbonate intermediate and the formal reinsertion of CO 2 .

A Noble‐Metal‐Free Metal–Organic Framework (MOF) Catalyst for the Highly Efficient Conversion of CO2 with Propargylic Alcohols

“…[1] As ar esult, much effort has been devoted to developing effective methods to chemical fixation of CO 2 ,m ainly including the cycloaddition of epoxides or aziridines with CO 2 , [2] and carboxylation of terminal alkyne molecules with CO 2 . [3] Recently,the cyclization of propargylic alcohols with CO 2 has also aroused intense interest, [4] because the resultant products a-alkylidene cyclic carbonates are ac lass of important heterocyclic compounds in nature products synthesis,p harmaceutical chemistry,a nd polymers, such as b-ketocarboxylic acids, [5] nitropyrrolins A-E, [6] 2cyclopentenones, [7] poly(urethane)s and poly(carbonate)s. [8] However,o wing to the thermodynamic stability of C = O bond (bond enthalpy + 805 kJ mol À1 )a nd stable electronic structure of p 4 3 in CO 2 ,highly active catalysts are often needed in promoting this cyclization reaction, like Ag nanoparticles, [9] Ag salts, [10] and Ag-MOF or nanoparticle Ag@MOFs, [11] and it should be noted that most of these catalysts are associated with noble metal Ag. Therefore,t or educe the cost, the explorations on efficient catalysts with free noble metals are still highly desirable but ag reat challenge.…”

On Sustainability Aspects of the Synthesis of Five-Membered Cyclic Carbonates

“…Generally, temperatures ranging from 25 to 100 °C and CO 2 pressures up to 50 atm, as well as specific equipment, are required. The protocols discussed herein ,− report reasonably good yields ranging from 70% to 98%. In addition, according to the nature of the propargyl alcohol used in the protocol (primary, secondary, and tertiary), different reaction conditions are described to yield the desired product.…”

Katalytische Umwandlung von funktionalisierten cyclischen organischen Carbonaten

“…[50] 3.6. Der wichtigste Unterschied zur decarboxylierenden Umsetzung von VCCs besteht darin, dass alle Atome des Carbonat-Substrats im Endprodukt erhalten bleiben (Schema 17), d. h. hierbei handelt es sich um keine decarboxylierende Umwandlung.D ie Anwesenheit von Me 2 Al(OMe) ist entscheidend fürd ie selektive Bildung von b-Ketocarbonsäuren und anderen organometallischen Reagenzien wie Me 3 Bu nd Me 2 Zn, die sich als weniger erfolgreich erwiesen.…”

“…[46] Vorkurzem berichteten Ackermann und Mitarbeiter über eine Domino-C-H/N-H-Allylierung von Arylimidaten mit vielseitigen Cobalt(III)-Katalysatoren (Schema 14). [ [50] 3.6. Umwandlung von alkinylsubstituierten cyclischen Carbonaten Verglichen mit den VCCs ist die Auswahl an Literatur zur Übergangsmetall-vermittelten Umwandlung ihrer Alkinyl-Kongenere deutlich begrenzt, trotz der Attraktivitätd ieser Bausteine fürd ie Synthese.D ie Reaktivitätv on alkinylsubstituierten cyclischen Carbonaten wurde erstmals 1994 beschrieben als Dixneuf und Mitarbeiter von der Pd-katalysierten Bildung von Alkinyl-a-allenolen aus alkinylsubstituierten cyclischen Carbonaten und terminalen Alkinen berichteten.…”