7746-94-3Relevant academic research and scientific papers
One-Pot γ-Lactonization of Homopropargyl Alcohols via Intramolecular Ketene Trapping
Yamane, Daichi,Tanaka, Haruna,Hirata, Akihiro,Tamura, Yumiko,Takahashi, Daichi,Takahashi, Yusuke,Nagamitsu, Tohru,Ohtawa, Masaki
, p. 2831 - 2835 (2021/05/05)
A one-pot γ-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation/oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the γ-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot lactonization.
Cooperative iodine and photoredox catalysis for direct oxidative lactonization of carboxylic acids
Duhamel, Thomas,Mu?iz, Kilian
supporting information, p. 933 - 936 (2019/01/23)
A new method for the formation of γ- and δ-lactones from carboxylic acids through direct conversion of benzylic C-H to C-O bonds is described. The reaction is conveniently induced by visible light and relies on a mild cooperative catalysis by the combination of molecular iodine and an organic dye.
Electroreductive coupling of aromatic ketones, aldehydes, and aldimines with α,β-unsaturated esters: Synthesis of 5-aryl substituted γ-butyrolactones and lactams
Kise, Naoki,Hamada, Yusuke,Sakurai, Toshihiko
, p. 1143 - 1156 (2017/02/18)
The electroreductive intermolecular coupling of aromatic ketones and aldehydes with α,β-unsaturated esters in the presence of TMSCl gave the adducts as γ-trimethylsiloxy esters. The detrimethylsilylation of the adducts with TBAF afforded 5-aryl substituted γ-butyrolactones. The electroreductive coupling of N-(4-methoxyphenyl)-1-arylmethaneimines with methyl acrylate in the presence of TMSCl gave the adducts as methyl 4-aryl-4-((4-methoxyphenyl)amino)butanoates. The adducts were transformed to 5-aryl-γ-butyrolactams by cyclization with NaH and subsequent oxidation with CAN. (±)-Norcotinine was prepared from nicotinaldehyde by this method. The electroreductive coupling of aromatic ketones and aldimines with acrylonitrile in the presence of TMSCl gave 4-aryl-4-(trimethylsiloxy)butanenitriles and 4-aryl-4-((4-methoxyphenyl)amino)butanenitriles, respectively.
Nucleo-Palladation-Triggering Alkene Functionalization: A Route to γ-Lactones
Zheng, Meifang,Chen, Pengquan,Huang, Liangbin,Wu, Wanqing,Jiang, Huanfeng
, p. 5756 - 5759 (2017/11/10)
An unprecedented strategy for the highly effective synthesis of γ-lactones from homoallylic alcohols was achieved by palladium catalysis in one step. The protocol affords aryl, alkyl, and spiro γ-lactones directly from readily available homoallylic alcohols in good yields with excellent functional group tolerance and high chemoselectivity under mild conditions.
Visible-Light-Induced Aza-Pinacol Rearrangement: Ring Expansion of Alkylidenecyclopropanes
Liu, Wen-Deng,Xu, Guo-Qiang,Hu, Xiu-Qin,Xu, Peng-Fei
, p. 6288 - 6291 (2017/12/08)
A novel visible-light-induced aza-pinacol rearrangement was developed for the first time. In this approach, the addition of the N-centered radical to the C=C bond of alkylidenecyclopropanes delivers a variety of cyclobutanimines and γ-butyrolactones, with
Direct Synthesis of 2-Formylpyrrolidines, 2-Pyrrolidinones and 2-Dihydrofuranones via Aerobic Copper-Catalyzed Aminooxygenation and Dioxygenation of 4-Pentenylsulfonamides and 4-Pentenylalcohols
Wdowik, Tomasz,Chemler, Sherry R.
supporting information, p. 9515 - 9518 (2017/07/25)
A new method for the direct conversion of 4-pentenylsulfonamides to 2-formylpyrrolidines and a 2-ketopyrrolidine has been developed. This transformation occurs via aerobic copper-catalyzed alkene aminooxygenation where molecular oxygen serves as both oxidant and oxygen source. The 2-formylpyrrolidines can further undergo oxidative carbon-carbon bond cleavage in situ upon addition of DABCO, providing 2-pyrrolidinones. These transformations have been demonstrated for a range of 4-pentenylsulfonamides. 4-Pentenylalcohols also undergo oxidative cyclization to form γ-lactones predominantly. The reaction is chemoselective, oxidizing one alkene in the presence of others, and is compatible with several functional groups. Application of these reactions to the formal syntheses of baclofen and (+)-monomorine was demonstrated.
Copper-Catalyzed Formal [2+2+1] Heteroannulation of Alkenes, Alkylnitriles, and Water: Method Development and Application to a Total Synthesis of (±)-Sacidumlignan D
Ha, Tu M.,Chatalova-Sazepin, Claire,Wang, Qian,Zhu, Jieping
supporting information, p. 9249 - 9252 (2016/08/05)
A copper-catalyzed three-component reaction of alkenes, alkylnitriles, and water affords γ-butyrolactones in good yields. The domino process involves an unprecedented hydroxy-cyanoalkylation of alkenes and subsequent lactonization with the creation of three chemical bonds and a quaternary carbon center. The synthetic potential of this novel [2+2+1] heteroannulation reaction was illustrated by a concise total synthesis of (±)-sacidumlignan D.
MnO2-promoted carboesterification of alkenes with anhydrides: A facile approach to γ-lactones
Wu, Lihuan,Zhang, Zhenming,Liao, Jianhua,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
supporting information, p. 2628 - 2631 (2016/02/18)
An efficient carboesterification of alkenes with anhydrides promoted by MnO2 has been developed to afford functionalized γ-lactones in good to excellent yields. This method shows a broad substrate scope and provides a valuable and convenient synthetic tool for constructing γ-lactones.
Copper-catalyzed aerobic C-C bond cleavage of lactols with N-hydroxy phthalimide for synthesis of lactones
Tnay, Ya Lin,Chiba, Shunsuke
supporting information, p. 873 - 877 (2015/04/14)
The transformation of cyclic hemiacetals (lactols) into lactones has been achieved by Cu-catalyzed aerobic C-C bond cleavage in the presence of N-hydroxy phthalimide (NHPI). The present process is composed of a multistep sequence including a) formation of exo-cyclic enol ethers by dehydration; b) addition of phthalimide N-oxyl radical to the enol ethers followed by trapping of the resulting C-radicals with molecular oxygen to form peroxy radicals; c) reductive generation of oxy radicals and subsequent β-radical fragmentation to generate lactones.
Insight into the mechanism and stereochemistry of the transformations of alkyltitanium Ate-Complexes. An enhanced enantioselectivity in the cyclopropanation of the carboxylic esters with titanacyclopropane reagents
Kulinkovich, Oleg G.,Kananovich, Dzmitry G.,Lopp, Margus,Snieckus, Victor
supporting information, p. 3615 - 3626 (2015/01/16)
The dependence of the stereoselectivity of the cyclopropanation reaction of g,g-diphenyl-g-butyrolactone and carboxylic esters with alkylmagnesium bromides in the presence of titanium(IV) TADDOLates on the structure of the reactants has been examined in d
