Rhenium-catalyzed allylation of C–H bonds of benzoic and acrylic acids

Abstract

We have succeeded in the allylation of aromatic and olefinic C-H bonds of benzoic and acrylic acids using a rhenium catalyst, Re(2)(CO)(10). In this reaction, isomerization of the introduced allyl group to the 1-propenyl group did not occur.

Methyl Salicylate as a Selective Methylation Agent for the Esterification of Carboxylic Acids

“…The protocol was also applied to the esterification of methacrylic acid and cinnamic acid, giving the desired methyl methacrylate (3u) and methyl cinnamate (3v) in 72% and 79% yield respectively (entries 21 and 22). Finally, the methylation of carboxylic acids with a heteroarene, 1H-indol-3-ylacetic acid, pyridine-3-carboxylic acid, and thiophene-2-carboxylic acid, gave the corresponding esters 3w, 3x, and 3y in 79%, 81%, and 83% yields, respectively, under the same reaction conditions (entries [23][24][25]. Notably, when the reaction was completed, salicylic acid was readily recovered as a white precipitate after hydrolysis of the excess of methyl salicylate, extraction of the reaction mixture, and acidification of the aqueous phase with hydrochloric acid.…”

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

“…Beispielsweise wurde unabhängig voneinander von Miura, Zhang und Sawamura gezeigt, dass sich elektronenarme Arene, wie Polyfluorarene und Azole, in Gegenwart eines Kupfer- [6] oder Palladiumkatalysators [7] allylieren lassen (Schema 1 c). Ebenfalls ist die Ruthenium- [8] und Rhenium-katalysierte [9] ortho-Allylierung von 2-Phenylpyridinen beziehungsweise Benzoaten bei hohen Temperaturen bekannt. Jedoch wurden ein signifikantes Ausmaß an Doppelbindungsverschiebung, eine schlechte Regioselektivität und/oder eine begrenzte Substratbreite beobachtet.…”

Rhodium-catalyzed mild and selective C–H allylation of indolines and indoles with 4-vinyl-1,3-dioxolan-2-one: facile access to indolic scaffolds with an allylic alcohol moiety

“…5 The transition-metal-catalyzed CeH bond functionalization has emerged as a powerful tool creating the intricate organic molecules due to its remarkable potential for step economy and environmental sustainability. 6 With the development of catalytic CeH bond functionalization, the direct CeH allylations have been achieved under various metal catalysis such as Rh, 7 Ir, 8 Ru,9 Pd,10 Re, 11 Cu, 12 Ni, 13 and Co 14 (Fig. 1).…”