Unprecedented Reactivity of β‐Iodovinyl Sulfones: An Efficient Synthesis of β‐Keto Sulfones and β‐Keto Thiosulfones

Abstract

An unprecedented reactivity of (E)‐β‐iodovinyl sulfones in the presence of NaOAc is reported. The (E)‐β‐iodovinyl sulfones were treated with NaOAc in DMSO/H2O to yield β‐keto sulfones in moderate to high yields. A novel oxidative difunctionalization of β‐iodovinyl sulfones with thiosulfonates and NaOAc in DMF has been developed. This metal‐free oxosulfenylation is an operationally simple to access a wide range of β‐keto thiosulfones (α‐thioaryl‐β‐keto sulfones) in moderate to high yields. The transformations were reliable at gram‐scale, thus illustrating its efficiency and practicality. A plausible mechanism for the protocol is also proposed.

Transition Metal‐Free Sulfenylation of C−H Bonds for C−S Bond Formation in Recent Years: Mechanistic Approach and Promising Future

“…Similarly, transition metal‐free, regioselective and sodium acetate mediated sulfenylation of β ‐iodovinyl sulfones ( 233 ) have been reported by Reddy and co‐workers [189] by using thiosulfonates ( 234 ) as sulfenylating reagent. They have developed a novel and mild method for the synthesis of β ‐keto thiosulfones ( 235 ) using β ‐iodovinyl sulfones and thiosulfonates.…”

Research Progress in C—S Bond Formation Reaction of Olefins with Organic Sulfur Reagents under Photocatalyst-Free and Non-Electrochemical Conditions

“…不仅如此, 由于 其稳定好, 硫代磺酸酯还是一类有效构建 C-S 键的合 成子 [67] . Reddy 课题组 [68] 以 N,N-二甲基甲酰胺(DMF)为 溶剂, 醋酸钠为添加剂, 通过 β-碘代砜类化合物和硫代 磺酸酯反应, 合成了一系列 β-硫醚砜基双取代的酮类化 合物, 产率大部分大于 70% (Eq. 29).…”

Pd‐Catalyzed Annulation of β‐Iodovinyl Sulfones with 2‐Halophenols: A General Route for the Synthesis of 3‐Sulfonyl Benzofuran Derivatives

“…As part of our ongoing research programme on organosulfur chemistry, we, herein, report an efficient and unique palladium‐catalysed annulation of β‐iodovinyl sulfones with 2‐halophenols to produce 3‐sulfonyl benzofuran derivatives through the tandem construction of C−O and C−C bonds in a single synthetic operation. Thus, the required β‐iodovinyl sulfones are easily accessible from broadly available alkynes, but their synthetic utility has not been much explored …”

“…[a] Reactions were performed on a 0.5 mmol scale of 1 a – p (1.0 equiv), 2 a / b (1.5 equiv), Pd(OAc) 2 (10 mol%), Ph 3 P (20 mol%), Cs 2 CO 3 (2.0 equiv) in DMF (2.5 mL) under N 2 at 120 °C for 4–6 h. [b] Isolated yield. [c] 3 kb contaminated with corresponding β‐keto sulfone (see the Supporting Information).…”

“…Based on the above experimental results and the literature precedent, a plausible mechanism for this tandem process is proposed (Scheme ). Firstly, base‐promoted oxa‐Michael addition of β‐iodovinyl sulfone ( 1 a ) with 2‐bromophenol 2 a could form enol ether ( E ‐ 3 a ). Secondly, the mechanism starts with the consist of oxidative insertion of E ‐ 3 a to the in situ generated zerovalent palladium (PdL n ) species to form the arylpalladium complex ( A ) .…”