81141-07-3Relevant academic research and scientific papers
Visible Light-Induced α-C(sp3)-H Acetalization of Saturated Heterocycles Catalyzed by a Dimeric Gold Complex
Si, Xiaojia,Zhang, Lumin,Wu, Zuozuo,Rudolph, Matthias,Asiri, Abdullah M.,Hashmi, A. Stephen K.
, p. 5844 - 5849 (2020)
Saturated heterocyclic acetals are useful fragments in organic synthesis and other fields. Herein, C(sp3)-H dehydrogenative cross-couplings of ethers, tetrahydrothiophenes, and pyrrolidines were achieved under visible light irradiation by using iodobenzene and an in situ-formed gold complex. The broad functional group compatibility and substrate scope indicate that our strategy is a promising way to synthesize acetal analogues. The method was successfully applied in late-stage modifications of bioactive molecules. Gram scale syntheses and mechanistic studies are also presented.
MIXED AROMATIC-ALIPHATIC ACETALS; THEIR PREPARATION, (1)H AND (13)C-NMR SPECTRA AND HYDROGENOLYSIS BY ETHEREAL SOLUTION OF CHLOROALANE
Dusek, Jiri,Sklenar, Vladimir,Jonas, Jaroslav
, p. 2912 - 2923 (2007/10/02)
The corresponding p-X-phenylisobutyl acetals of acetaldehyde (I), 2-(p-X-phenoxy)tetrahydropyrans (II), 2-(p-X-phenoxy)tetrahydrofurans (III), and cyclohexyl(p-X-phenyl)acetals of acetaldehyde (IV) were prepared by addition of p-X-substituted phenols to isobutyl vinyl ether, 2,3-dihydro-4H-pyran, 2,3-dihydrofuran, and cyclohexyl vinyl ether, respectively.The structures of acetals I-IV were confirmed by their (1)H and (13)C-NMR spectra.Diastereotopic protons of the methylene and geminal methyl groups are anisochronous in the (1)H-NMR spectra of acetals I. (13)C-NMR spectra of acetals IV demonstrate anisochronous behaviour of cyclohexane ring diastereotopic carbon atoms.The constants ?p+ for several groups calculated using (13)C-NMR spectra are: 1-isobutoxy-1-ethoxy- (-0.58), 2-tetrahydrofuryloxy- (-0.59), and 1-cyclohexyloxy-(1-ethoxy) (-0.57).Experimental relative rate constants of hydrogenolysis of acetals I and II by ethereal solution of chloroalane yield best correlations with ?p+ constants of the substituent X, providing the values ρ= -1.09 for compounds of the series I and II, respectively.The importance of these results for finding the rate determining step of the studied reaction is discussed.
