Ru‐Catalyzed O‐H Insertion of Sulfoxonium Ylide and Carboxylic Acid to Synthesize α‐Acyloxy Ketones

Abstract

Scheme 1. The reactions of sulfur ylide and carboxylic acid. Scheme 2. Proposed reaction mechanism.

Carboxylic Acid Functionalization Using Sulfoxonium Ylides as a Carbene Source

“…The scope of benzoic acids for a terminal sulfoxonium ylide 7a was investigated using [VO­(acac) 2 ] (Scheme ). Terminal sulfoxonium ylide 7a was synthesized using the reported literature procedure. , 7a (0.5 mmol, 1 equiv) reacted with benzoic acids (0.5 mmol, 1 equiv) in CH 3 CN (0.25 M) and obtained lower yields with 5 mol % of the [VO­(acac) 2 ] catalyst. Therefore, we increased the catalyst load up to 10 mol %, which also resulted in lower yields of the acid-functionalized products.…”

“…Sulfoxonium ylides, which are more C-nucleophilic than the corresponding diazo compounds, have earned much recognition as they are stable, crystalline solids producing only DMSO as the byproduct during the metal-carbenoid formation. − There are only a few reports for the reaction of sulfoxonium ylides with benzoic acids. Mu et al devised a method for synthesizing α-acyloxy ketones using ruthenium as a catalyst from sulfoxonium ylides …”

Enantioselective Indole Insertion Reactions of α-Carbonyl Sulfoxonium Ylides

“…25 No reaction occurred when silanediol (4) or cinchona thiourea (5) catalysts were used, while a low yield and the racemic product were produced in the case of the squaramide catalyst (6). The thiourea catalyst (7) and the urea catalyst (8) led to low enantioselectivities, while thiourea catalyst (9), a catalyst we have had success with in the past, gave more promising results with 40% ee. Phosphoric acid catalysts proved to be the best for this reaction where the VAPOL backbone catalyst (10) gave a moderate yield and enantioselectivity (43% and 46%, respectfully).…”

“…The use of sulfoxonium ylides continues to be an area of exploration due to their attractive reactivity patterns and their ability to act as safer alternatives to metallocarbene and diazo chemistry. − A range of N–H, , B–H, and O–H bond-insertion reactions have been developed, often utilizing transition metal catalysis. Recently, the Mattson and Burtoloso group described the first organocatalytic enantioselective X–H insertion reaction from a sulfoxonium ylide, which used chiral thiourea as the catalyst.…”

N-Heterocyclic Carbene (NHC)/Ag(I) Co-catalyzed Synthesis of 2-Oxo-2-arylethyl Aryl Formates

“…近年来, 化学家们开发了一 些合成 2-氧代-2-芳乙基芳甲酸酯及其类似物的方法 [9] . 其中利用卤代芳基乙酮和芳基甲酸反应是合成 2-氧代-2-芳乙基芳甲酸酯传统方法之一 [10] , 此外还有铵盐催化 的芳基乙烯和苯乙酮的反应 [11] , 铵盐催化苯乙烯的直接 转化 [12] , 金配合物催化的芳基乙炔和芳酸的反应 [13] , 金 属催化的羰基化合物分别与硫叶立德 [14] 、烯胺酮 [15] 、端 炔 [16] 的反应, 单质碘与过氧叔丁醇复合催化体系介导 的碘代苯乙酮和甲苯分子间氧化偶联 [17] 、苯乙酮分子间 的自氧化偶联等 [18] . 但上述合成方法在产物生成效率、 使用过量氧化剂和产物多样性等方面仍然存在一些不 足, 继续寻找更加有效合成 2-氧代-2-芳乙基芳甲酸酯 的方法是有机合成研究领域的重要内容之一.…”