20453-83-2Relevant academic research and scientific papers
Tertiary alkylations of aldehydes, ketones or imines using benzylic organoboronates and a base catalyst
Nagao, Kazunori,Nakamura, Kei,Ohmiya, Hirohisa,Sato, Yukiya,Yabushita, Kenya
, p. 1065 - 1069 (2020/11/09)
The KHMDS-catalyzed tertiary alkylation of aldehydes, ketones or imines using tertiary benzylic organoboronates is reported. This protocol permitted the use of tertiary benzylic alkylboronates as the tertiary alkyl anion for construction of highly congested contiguous sp3 carbon centers. The mild and transition-metal-free reaction conditions are attractive features of the protocol.
Visible-Light Photoredox-Catalyzed Hydroalkoxymethylation of Activated Alkenes Using α-Silyl Ethers as Alkoxymethyl Radical Equivalents
Khatun, Nilufa,Kim, Myeong Jun,Woo, Sang Kook
, p. 6239 - 6243 (2018/09/27)
A new neutral silicon-based traceless activation group (TAG) for visible-light photoredox-catalyzed hydroalkoxymethylation of alkenes is presented. This reaction involves in-situ-generated alkoxymethyl radical via single electron oxidation (SET) of α-TMS-substituted ethers, followed by subsequent conjugate addition to activated alkenes. Various functional groups were tolerated both under mild metal and metal-free conditions to provide good to excellent yields. Furthermore, the addition products were transformed to valuable synthetic building blocks, such as carboxylic acids,-butyrolactones, and complex aryl alkyl ethers.
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.
Carbene catalyzed umpolung of α,β-enals: A reactivity study of diamino dienols vs. azolium enolates, and the characterization of advanced reaction intermediates
Yatham, Veera Reddy,Neud?rfl, J?rg-M.,Schl?rer, Nils E.,Berkessel, Albrecht
, p. 3706 - 3711 (2015/06/25)
Since their discovery by Bode and Glorius in 2004, N-heterocyclic carbene catalyzed conjugate umpolung reactions of α,β-enals have been postulated to involve the formation of diamino dienols ("homoenolates") and/or azolium enolates ("enolates"), typically followed by addition to electrophiles, e.g. Michael-acceptors. In this article, we provide evidence, for the first time, for the postulated individual and specific reactivity patterns of diamino dienols (γ-C-C-bond formation) vs. azolium enolates (β-C-C-bond formation). Our study is based on the pre-formation of well defined diamino dienols and azolium enolates, and the in situ NMR monitoring of their reactivities towards enone electrophiles. Additionally, reaction intermediates were isolated and characterized, inter alia by X-ray crystallography.
Mn(OAc)3-mediated arylation-lactonization of alkenoic acids: Synthesis of γ,γ-disubstituted butyrolactones
Gao, Yuzhen,Xu, Jian,Zhang, Pengbo,Fang, Hua,Tang, Guo,Zhao, Yufen
, p. 36167 - 36170 (2015/05/05)
A general method for the oxidative cyclization of 4-alkenoic acids with arylboronic acids has been developed. The reactions described provide a novel access to γ,γ-disubstituted butyrolactones in moderate yields, and allow the direct formation of a C-C bo
Multiple rhodium-catalyzed cleavages of single C-C bonds
Aissa, Christophe,Crepin, Damien,Tetlow, Daniel J.,Ho, Kelvin Y. T.
supporting information, p. 1322 - 1325 (2013/04/23)
The Rh(I)-catalyzed intramolecular hydroacylation of cis and trans asymmetrically substituted alkylidenecyclobutanes proceeds according to three mechanistic pathways. As shown by deuterium-labeling experiments, the mechanism accounting for the rearrangeme
Benzotriazole- and 1,2,4-triazole-stabilized allylic anions: Applications in syntheses of functionalized α,β-unsaturated ketones, γ-lactones, γ-lactams, and β-substituted esters
Katritzky,Feng,Lang
, p. 706 - 714 (2007/10/03)
Deprotonated 1-(benzotriazol-1-yl)-1-ethoxy-2-hexene (7) reacted with alkyl halides, aldehydes, ketones, imines, and α,β-unsaturated esters to give exclusively the α-alkylated products 8a-c, 10a,b, 12, 14, 16, and 18a,b, respectively. Without isolation, these products were hydrolyzed under mild conditions to generate the corresponding simple or functionalized α,β-unsaturated ketenes 9a-c, 11a,b, 13, 15, 17, and 19a,b. Similar reactions with the phenyl-substituted analog 3-(benzotriazol-1-yl)-3-ethoxy-1-phenyl-1-propene (21) also gave the analogous α-products, but they were accompanied by small amounts of the γ-products in most cases. By contrast, deprotonation of the corresponding triazole derivative 29 with butyllithium followed by reactions with alkyl halides, aldehydes, ketones, or imines yielded exclusively γ-alkylated adducts 32, 34, 36, 38, 40, and 42. Intermediates 32, 34, 36, 38, 40, and 42 were readily converted into β-substituted esters 33a-c, γ-lactones 35a,b, 39, 41, and 43, and γ-lactams 37a-c on hydrolysis.
Novel Carboxymethylation of Styrene Derivatives by Mn(3+)-Mediated Electrooxidation
Shundo, Ryushi,Nishiguchi, Ikuzo,Matsubara, Yoshiharu
, p. 185 - 188 (2007/10/02)
Anodic oxidation in a mixed solvent of acetic acid and acetic anhydride containing a variety of styrene derivatives, small amounts of Mn(OAc)2*4H2O and Cu(OAc)2*H2O brought about a facile carboxymethylation to give the corresponding γ-butyrolactones as the main products in good yields.
