920957-35-3Relevant academic research and scientific papers
All at once arrangement of both oxygen atoms of dioxygen into aliphatic C(sp3)-C(sp3) bonds for hydroxyketone difunctionalization
Qiao, Xiaofeng,Lin, Yuhan,Li, Jiazhen,Ma, Wanhong,Zhao, Jincai
, p. 770 - 777 (2021/04/09)
Both β- and γ- hydroxyketone structures are important units in biologically active molecules, synthetic drugs and fine chemicals. Although there are some routes available for their manufacture from pre-functionalized groups on one or two matrix molecule(s), the approaches to simply and simultaneously deposit two oxygen atoms from dioxygen into two specific C(sp3) positions of pure saturated hydrocarbons have rarely succeeded because they are involved in the targeted activation of three inert C-H σ bonds all at once. Here, we show that a TiO2-CH3CN photocatalytic suspension system enables the insertion of dioxygen into one C(sp3)-C(sp3) bond of strained cycloparaffin derivatives, by which difunctionalized hydroxyketone products are obtained in a one-pot reaction. With the cleavage event to release strain as the directional driving force, as-designed photocatalytic reaction systems show 21 examples of β-hydroxyketone products with 31%–76% isolated yields for three-membered ring derivatives and 5 examples of γ-hydroxyketone products with 30%–63% isolated yields for four-membered ring substrates. 18O isotopic labeling experiments using 18O2, Ti18O2 and intentionally added H218O, respectively, indicated that both oxygen atoms of hydroxyketone products were exclusively from dioxygen, suggesting a previously unknown H+/TiO2-e? catalyzed arrangement pathway of the hydroperoxide intermediate to convert dioxygen into hydroxyketone units. [Figure not available: see fulltext.]
Metal-Free tert -Butyl Hydrogenperoxide (TBHP) Mediated Radical Alkylation of Enol Acetates with Alcohols: A New Route to β-Hydroxy Ketones
Tang, Yucai,Fan, Yuanyuan,Zhang, Ye,Li, Xiaoqing,Xu, Xiangsheng
, p. 1860 - 1863 (2016/07/16)
A metal-free TBHP-mediated radical alkylation of enol acetates with alcohols is described. This method provides a new route to a variety of β-hydroxy-ketones in moderate to good yields.
Experimental and theoretical studies of a one-flask synthesis of 3H-1-benzazepines from 2-haloanilines and α,β-unsaturated ketones
Ramig, Keith,Greer, Edyta M.,Szalda, David J.,Razi, Rabail,Mahir, Fahima,Pokeza, Nataliya,Wong, Wei,Kaplan, Benjamin,Lam, Joanne,Mannan, Ayesha,Missak, Christopher,Mai, Dat,Subramaniam, Gopal,Berkowitz, William F.,Prasad, Prakash,Karimi, Sasan,Lo, Ngai Hin,Kudzma, Linas V.
experimental part, p. 2363 - 2371 (2010/07/04)
3H-1-Benzazepines are prepared in one step from the reaction of 2-fluoro- or 2-chloroaniline and several aryl vinyl ketones. Enones 9a-c gave benzazepines 11a-c as expected, showing that alkyl substitution at C4 and C5 in the benzazepines is possible. However, enone 9d underwent decomposition due to conjugate addition of the 2-fluoroaniline, while enone 10 gave unsaturated imine 12 as the only product able to be isolated. The failure of unsaturated imine 12 to undergo cyclization may indicate that placement of an alkyl group at C3 of the benzazepines may not be possible. Isolation of by-products buttressed by a computational study verifies a postulated, multi-step process for benzazepine formation: a [1,5] sigmatropic shift in fluoroimine 3, addition elimination to give carbocation 15, formation of the unstable 5H-1-benzazepine 7, and acid-catalyzed isomerization to give the stable 3H-1-benzazepine 2. The calculations also indicate why unsaturated imine 12 fails to cyclize. NMR spectroscopic experiments show that the 3H-benzazepines undergo fast conformational exchange on the NMR time scale at room temperature except when there is an alkyl substituent at C5.
