Recent Advances in Acyl Suzuki Cross-Coupling

Abstract

Acyl Suzuki cross-coupling involves the coupling of an organoboron reagent with an acyl electrophile (acyl halide, anhydride, ester, amide). This review provides a timely overview of the very important advances that have recently taken place in the acylative Suzuki cross-coupling. Particular emphasis is directed toward the type of acyl electrophiles, catalyst systems and new cross-coupling partners. This review will be of value to synthetic chemists involved in this rapidly developing field of Suzuki cross-coupling as well as those interested in using acylative Suzuki cross-coupling for the synthesis of ketones as a catalytic alternative to stoichiometric nucleophilic additions or Friedel-Crafts reactions.

Kinetically Controlled, Highly Chemoselective Acylation of Functionalized Grignard Reagents with Amides by N−C Cleavage

“…[5] In this context, the discovery that amide functionalization can be accomplished by the direct insertion of at ransition-metal to give the acyl-metal intermediate from historically unreactive amide bonds (nN!p * C=O delocalization) was an important achievement that enabled the constructiono fi mportant motifs for chemical synthesis ( Figure 1B). [6,7] Continuing this theme, herein, we reportt he third mode of reactivity of amide bonds, wherein the direct, highly chemoselective, transitionmetal-free acylation of amides with functionalized Grignardr eagents [8] is accomplished by transientt etrahedrali ntermediates underk inetic control( Figure 1C). [9,10] The reactione nables the construction of aw ide variety functionalized ketonesw ith excellentf unctional-groupt olerance, including ester,c yano, nitro, chloro, bromo, thiomethyl, tosyl, amino, and trifluoromethyl ether,a nd sets the stage for using amidesa sa cylating reagents in an alternative paradigm to the metal-chelated approach [4,5] and acyl-metals.…”

Catalytic C−H/C−F Coupling of Azoles and Acyl Fluorides

“…Transition‐metal‐catalyzed cross‐coupling reactions of acyl electrophiles with aryl nucleophiles represent a powerful and reliable synthetic strategy for the introduction of acyl fragments into aromatic rings to provide aromatic ketones, and a large variety of carboxylic acid derivatives are currently used as acyl electrophiles . Among these, acyl fluorides have recently gained much attention as valuable carbon‐based electrophiles in cross‐coupling reactions, especially in acyl coupling and decarbonylative coupling reactions .…”

“…Transition-metal-catalyzed cross-couplingreactions of acyl electrophiles with aryl nucleophilesr epresent ap owerful and reliable synthetic strategy for the introductiono fa cyl fragments into aromatic rings to provide aromatick etones, and al arge variety of carboxylic acid derivatives are currently used as acyl electrophiles. [1][2][3][4][5][6][7][8][9][10][11][12][13] Amongt hese, acyl fluorides have recently gained much attention as valuablec arbon-based electrophiles in cross-couplingreactions, especially in acyl coupling [14][15][16][17] and decarbonylative coupling reactions. [17][18][19][20][21][22] Due to the moderate electrophilicity of acyl fluorides,t hey exhibit ag ood balance between stability and reactivity with respectt ot heir compatibility under nucleophilic conditions, that is, they are more stable than the commonly employed acyl chlorides, [4] yet more reactive than the corresponding esters [9, 13b] and amides.…”

“…Even though the combination of ap alladium and ac opperc atalyst is critical for the coupling, the addition of an auxiliary ligand is not essential, albeit that the yield slightly decreases in this case (entries 8-10). [27] Bases other than K 2 CO 3 ,f or example, KF,K 3 PO 4 , Na 2 CO 3 ,a nd CsF,a sw ell as the absence of ab ase, did not afford yields highert han that in the presence of K 2 CO 3 (entries [11][12][13][14][15].…”

Säurefluoride in der Übergangsmetallkatalyse: Balance von Stabilität und Reaktivität

“…[1] Die meisten Carbonsäurederivate,w ie Säuren, Acylhalogenide,A nhydride,E ster und Amide,w urden erfolgreich als elektrophile Partner in Kreuzkupplungen eingesetzt. [2][3][4][5][6][7] Im Vergleich zu anderen Säurehalogeniden oder -anhydriden weisen Säurefluoride eine hçhere Stabilitätg egen Wasser und neutrale Sauerstoffnukleophile auf,a ußerdem sind sie weniger anfällig für eine Racemisierung. In Gegenwart von Palladium(0)-, Nickel(0)-oder Iridium(I)-Komplexen erfolgt eine rasche oxidative Addition, die zu stark elektrophilen Acyl-Pd II -, Acyl-Ni II -b zw.A cyl-Ir III Aryl-, Heteroaryl-, Alkyl-und Alkenylketone 3 erfolgte in mäßigen bis hohen Ausbeuten.…”