α-Heteroarylation of Ketones <i>via</i> the Umpolung Reaction of <i>N</i>-Alkoxyenamine

Abstract

A new method has been developed for the umpolung α-heteroarylation of ketones via an N-alkoxyenamine. The treatment of ketones with tris(heteroaryl)aluminum reagents in the presence of isoxazolidine gave the corresponding α-heteroarylated ketones in moderate to good yields.

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

“…In line with this high importance associated with the molecules of current topic, i.e., more than one indole molecule flanked by a central atom, conglomeration of the available synthetic methods will have a high scientific value. This review will give a concise account of the same, although preparations of ionic bis(indolyl) metal salts will not be considered [24][25][26][27][28][29][30][31][32][33].…”

Regioselective Arene and Heteroarene Functionalization: N-Alkenoxypyridinium Salts as Electrophilic Alkylating Agents for the Synthesis of α-Aryl/α-Heteroaryl Ketones

“…α-Aryl/α-heteroaryl ketones are essential structures in a large proportion of small molecule drugs and bioactive molecules that have important applications on organic synthesis and pharmaceutical chemistry . This has led to the development of numerous elegant methods for the synthesis of α-aryl ketones, including the transition metal (Pd, Ni, or Cu)-catalyzed coupling reaction of aryl halides or arenes with ketones, diazo ketones, or enol silyl ethers, − the reaction of carbonyl compounds with diaryliodonium salts catalyzed by metal lithium salts, , and the α-arylation of ketones or ketone enolates − (Scheme , a). However, there are still some shortcomings that have limited the utility of these reactions in some cases: (1) The need for prefunctionalized aryl halide substrates and transition metal catalysts or reagents.…”

Transition-Metal-Free Intermolecular α-Arylation of Ketones via Enolonium Species

“…Enolate umpolung constitutes a rarely reported alternative for transition-metal-free arylation of enolates. Miyata reported the intermolecular α-arylation of in situ generated isoxazolidine enamines and reaction with 2 equiv of in situ generated triaryl or triheteroaryl aluminum reagents (i.e., 6 equiv of aromatic donor, Figure e). Recently, Maulide described an elegant lutidine N -oxide and triflic anhydride mediated intramolecular umpolung α-arylation of amides (Figure f) .…”