Katalytische Carbonylierungen: kein Bedarf an Kohlenmonoxid

Abstract

Erste bahnbrechende Erfolge in der metallorganischen Katalyse gelangen mit der Entdeckung der Roelen‐Reaktion 1938 (Hydroformylierung mit Kohlenmonoxid und Wasserstoff) und der Reppe‐Reaktion 1939 (Hydrocarboxylierung mit Kohlenmonoxid und Wasser). Seither haben Carbonylierungen mit Kohlenmonoxid einen festen Platz in der metallorganischen Chemie und der organischen Synthese. Allerdings ist die Verwendung von gasförmigem Kohlenmonoxid problematisch (toxisches Treibhausgas), sodass in neuerer Zeit Strategien zur Verwendung anderer Carbonylierungsreagentien entwickelt wurden. Dieser Kurzaufsatz beschreibt Carbonylierungen, die ohne direkten Einsatz von Kohlenmonoxid durchgeführt werden können.

Pentafluorobenzaldehyde and its utilizing in organic synthesis

“…Other syntheses of the complex compounds utilizing the PFBA were also published (Scheme 79 [569,[621][622][623][624][625][626][627][628][629][630][631][632][633][634][635][636]). Some of these compounds have catalytic action [632][633][634][635].…”

Domino Carbopalladation‐Carbonylation: Investigation of Substrate Scope

“…Attempts at the domino carbopalladation-carbonylation sequence for tetrasubstituted olefin 13. desired intermediate 3. Early carbonylation could potentially be avoided by generating CO slowly during the reaction or utilizing a CO surrogate; [23] however, the overall goal of this endeavour was to allow for the presence of pendant b-hydrogens and at atmospheric CO pressure b-hydride elimination was shown to out compete carbonylation for the trisubstituted analogues (Scheme 3). [7] Thus, the use of this method to construct vicinal quaternary centers remains elusive.…”

Convergent Synthesis of Azabicycloalkenones using Squaric Acid as Platform

“…[10] With desired cyclobutenediones in hand, we explored the decarbonylative transformation of these substrates. Toward this aim, we decided to use rhodium complexes as catalyst precursors for following reasons: (1) rhodium complexes catalyze intramolecular PK reactions under a CO pressure of less than 1 atm, [11] (2) rhodium catalysts are able to utilize carbonyl compounds as CO sources, [3] and finally, (3) rhodium complexes have proved to be effective for the ring transformation of cyclobutanones via C À C bond cleavage. [12] Thus, cyclobutenedione 2a was (Table 1).…”

“…Upon heating under the optimized conditions, 2b possessing a gem-disubstituted alkene was completely consumed within a reaction time of 60 h. Although the desired azabicycle 3b was again not separated from triphenylphosphine oxide, the yield of 3b proved to be 67 % according to the 1 H NMR analysis (run 2). A pure sample of 3b was obtained in 36 % yield using tri(p-methoxyphenyl)-phosphine instead of PPh 3 . In contrast, the reaction of the more sterically demanding vic-disubstituted alkene 2c did not reach to completion after 72 h and 3c was obtained in 29 % isolated yield together with recovered 2c (run 3).…”

“…[2] Furthermore, rhodiumcatalyzed PK reactions that utilize aldehydes as CO sources have been developed recently to avoid the direct use of harmful CO gas. [3] In this context, we envisioned that an alternative catalytic intramolecular PK-type reaction without the direct use of CO gas would be realized using squaric acid (SA) 1 as a platform (Scheme 1). In other words, the cyclobutenedione ring might be fully utilized as an acetylene dication equivalent as well as a CO source.…”