Milde Rhodium(III)‐katalysierte direkte C‐H‐Allylierung von Arenen mit Allylcarbonaten

Abstract

All(es)yl möglich! Die Titelreaktion unter Verwendung einfach erhältlicher Allylcarbonate bietet die Möglichkeit zur Allylierung elektronisch neutraler Arene und kombiniert vollständige γ‐Selektivität, hohe Isomerenverhältnisse und gute Substratbreite mit einer exzellenten Kompatibilität mit vielen funktionellen Gruppen.

Chiral Cp‐Rhodium(III)‐Catalyzed Asymmetric Hydroarylations of 1,1‐Disubstituted Alkenes

“…It is noteworthy that an allylic ester was a suitable substrate for this reaction and did not undergo ionization to the p-allyl species. [16] Moreover, hydrocarbon substituents on the olefin moiety, including ethyl and benzyl groups, did not interfere with the enantioselectivity. For some substrates, [17] the reaction had to be conducted at 50 8C because of lower reactivity or solubility.…”

Rhodium(III)‐Catalyzed Intramolecular Hydroarylation, Amidoarylation, and Heck‐type Reaction: Three Distinct Pathways Determined by an Amide Directing Group

“…Direct intermolecular C-H allylations have been demonstrated with a variety of metals but are limited by the necessity to use electron-deficient arenes or harsh conditions. More recently, allenes (Ir [15] and Rh III -catalyzed [16] ) and allyl carbonates (Rh III -catalyzed [17] ) have been used in directed C-H allylations. In contrast to the previous examples that use a variety of leaving groups on the allyl fragment, this pathway provides the allylated product from an allyl substrate by an oxidative pathway.…”

Mn‐Catalyzed Dehydrocyanative Transannulation of Heteroarenes and Propargyl Carbonates through C−H Activation: Beyond the Permanent Directing Effects of Pyridines/Pyrimidines

“…Introduction of Cy 2 NH as asecond base further improved the yield to 72 %with areduced amount of NaOAc. It was found that substrates with tBu or methyl carbonate groups were equally effective,while no desired reaction was observed with the parent propargyl alcohol or propargyl acetate (entries 11,14,15), at rend that has been observed in CÀH allenylation/allylation of arenes under Mn I and Rh III catalysis. Thehigh reactivity can be ascribed to the ligating effect of the carbonate group that facilitates b-oxygen elimination.…”

“…Thehigh reactivity can be ascribed to the ligating effect of the carbonate group that facilitates b-oxygen elimination. [15] In contrast, typical Cp*Rh III[11a,b] and Cp*Co III[11c] catalysts for C À Ha ctivation failed to exhibit any activity.…”