1488974-73-7Relevant academic research and scientific papers
Zinc Hydroxide-Catalyzed Asymmetric Allylation of Acetophenones with Amido-Functionalized Allylboronate in Water
Sengoku, Tetsuya,Maegawa, Ryunosuke,Imamura, Hiroki,Wada, Mitsuo,Yoda, Hidemi
, p. 2397 - 2418 (2020)
Enantioselective allylation of aldehydes and ketones is a widely used approach for preparing chiral homoallylic alcohols, however, most of the reactions are still mainly performed in organic solvents. Considering their environmental impact, expansion of synthetic technology in water has the highest priority in the organic chemistry field. Here, we report enantioselective reaction of water-stable amido-functionalized allylboronates with acetophenone derivatives in water. The reaction was catalyzed with zinc hydroxide and a didecylamino-functionalized chiral aminophenol reagent, affording a variety of homoallylic alcohols in up to 99% yield. There is a definite proportional correlation between the enantioselectivity and the size of an ortho-substituent on the substrate, and the enantiomeric excess of the product reached up to 98%. (Figure presented.).
Use of a (β-Amidoallyl)boronate as a Nucleophilic Reagent in Catalytic Enantioselective Addition to Isatins
Sengoku, Tetsuya,Sugiyama, Akihiro,Kamiya, Yuta,Maegawa, Ryunosuke,Takahashi, Masaki,Yoda, Hidemi
, p. 1285 - 1288 (2017)
Spirocycles are attractive synthetic targets for many synthetic chemists owing to their potent and promising biological activities. We previously reported a method for the highly enantioselective allylation of various isatins with β-amido-functionalized allylstannanes under the influence of indium-based chiral catalysts and applied this method to the synthesis of 2-oxindole derivatives spiro-fused to an α-methylene-γ-butyrolactone framework. In this communication, we report the successful development of a new catalytic system that enables enantioselective tin-free “amide allylation” with the aid of a newly prepared (β-amidoallyl)boronate for nucleophilic addition to isatins. This system consisting of a catalytic amount of diethylzinc as a competitive candidate in the presence of chiral 1,3-amino alcohols incorporating an acidic phenol functionality offers new opportunities for environmentally benign access to medicinally relevant spirocyclic 2-oxindoles.
Catalytic enantioselective amide allylation of isatins and its application in the synthesis of 2-oxindole derivatives spiro-fused to the α-methylene-γ-butyrolactone functionality
Takahashi, Masaki,Sengoku, Tetsuya,Yoda, Hidemi,Murata, Yusuke,Yagishita, Fumitoshi,Sakamoto, Masami
, p. 11091 - 11100,10 (2014/09/29)
This article is a full account of the work exploring the potential utility of catalytic enantioselective amide allylation of various isatins using indium-based chiral catalysts. A survey of various isatin substrates and NH-containing stannylated reagents revealed that the reaction has a remarkably wide scope to result in extremely high yields and enantioselectivities (up to >99 %, 99 % ee) of variously substituted homoallylic alcohols. Several mechanistic investigations demonstrated that the substrate-reagent hydrogen-bond interaction plays a critical role in the formation of the key transition states to result in enhanced catalytic reaction. The success of this approach allowed convenient access to chiral 2-oxindoles spiro-fused to the α-methylene- γ-butyrolactone functionality and their halogenated derivatives in almost enantiopure forms, thus highlighting the general utility of this synthetic method to deliver a large variety of antineoplastic drug candidates and pharmaceutically meaningful compounds.
