CuI‐Mediated α‐Ketoacylation of Sulfoximines under Solvent‐Free Conditions

Abstract

The first preparation of α‐ketoacyl sulfoximines under solvent‐free conditions using aryl ethanones and NH‐sulfoximines has been discovered and a series of desired 2‐oxo‐2‐arylacetyl sulfoximines were successfully synthesized in good to excellent yields (up to 93 %). The unprecedented protocol requires no extra solvents, bases, or additives and demonstrates outstanding compatibility with assorted functional groups (up to 27 examples). A plausible double catalytic cycle mechanism involving elemental iodine and copper is proposed; in‐situ generated aryl‐α‐iodo‐ethanone and a sulfoximine‐liganded‐CuII intermediate play important roles in C(sp3)–N coupling. The postulated mechanism is inspired by key experimental investigations detailed here.

Transition metal-free aroylation of NH-sulfoximines with methyl arenes

“…The product 3ya was formed by the radical procedure, while the compound 6a was generated through a C-H/N-H dual activations pathway. [15] As expected, with the addition of TEMPO, the yield of 3ya was depressed significantly and only trace was isolated while the yield of the product 6a arose to 48% (shown in the parentheses). Furthermore, the compatibilities of the substituents on the acetophenone were checked in the system, and the corresponding N- (2-oxo-2-arylacetyl)-sulfoximines 6b -6g were furnished in yields ranging from 41% -55% as shown in scheme 2.…”

“…In a similar manner, various functional groups on the meta-position of toluenes were also checked in the protocol. 3qa) and N-(3-nitrobenzoyl)sulfoximine (3ra) were successfully obtained, however, generally in lower yields, ranging from 59% to 80% (entries [13][14][15][16][17][18]. But N-(3,5dimethylbenzoyl)sulfoximine (3sa) was smoothly produced in good yield (91% for entry 19).…”

Use of Hypervalent Iodine Reagents in Visible Light-Promoted α-Ketoacylations of Sulfoximines with Aryl Alkynes

“…In light of these reports and on the basis of our long-lasting interest in sulfoximine chemistry, , we started wondering about N -linked α-ketoamide-type structures of type 1 . Such molecules have already been described, but in general accessing them involves harsh conditions with transition metal catalysis and strong oxidizing agents for the couplings and conversions of sp 3 carbons to the corresponding carbonyl fragments (Scheme c) . By a single transformation, we also demonstrated that N -alkynylated sulfoximines can be applied as starting materials; there as well, however, a metal complex {[Ru­( p -cymene)­Cl 2 ] 2 } was applied as the catalyst .…”

Silver-mediated Room Temperature Reactions for the Synthesis of N-α-Ketoacyl Sulfoximines and N-α,β-Unsaturated Acyl Sulfoximines

“…However, there are many reports related to the synthesis of N -acyl sulfoximines. , However, limited reports are available on the synthesis of N -α-ketoacyl sulfoximines. Zou et al and Cheng and Bolm reported the synthesis of N -α-ketoacyl sulfoximines by coupling methyl ketones and NH -sulfoximines in the presence of copper catalysts and oxidants under heating conditions. Later, Cheng and Bolm developed another method for synthesizing N -α-ketoacyl sulfoximines using sulfoximidoyl-containing hypervalent iodine reagents in the presence of light .…”