Conversion of 6-phenylimino-2H-thiopyran-4-amines to 1-phenyl-2,3-dihydro-4(1H)-pyridinones
摘要:
6-Phenylimino-3,6-dihydro-2H-thiopyran-4-amines (1) were converted to 1-phenyl-5,6-dihydropyridine-2(1H)-thiones (3). Those were akylated and hydrolyzed, thus yielding 6-melhylthio-1-phenyl-2,3-dihydro-4(1H)-pyridinones (5). Finally, the methylthio group was removed with Raney nickel giving the title compounds 6. The relative configurations of the formed diastereoisomeric dihydropyridinones have been investigated by NOE measurements.
Scandium(III)‐Zeolites as New Heterogeneous Catalysts for Imino‐Diels–Alder Reactions
作者:Andrea Olmos、Benoit Louis、Patrick Pale
DOI:10.1002/chem.201103624
日期:2012.4.16
demonstrates the first zeolite‐catalyzed synthesis of piperidine derivatives, including peptidomimetics and indoloquinolizidine alkaloids. The approach developed utilizes a highly effective one‐pot reaction cascade, through imine formation and imino‐Diels–Alderreactions, promoted by scandium‐loaded zeolites as a heterogeneouscatalyst. The methodology described benefits from very low catalyst loadings (≤5 mol %
Brønsted acid-catalyzed aza Diels-Alder reaction of Danishefsky's diene with aldimine generated in situ from aldehyde and amine in aqueous media
作者:Takahiko Akiyama、Jun Takaya、Hirotaka Kagoshima
DOI:10.1016/s0040-4039(99)01630-5
日期:1999.10
Three-component aza Diels-Alderreaction, starting from aldehyde, aniline, and Danishefsky's diene, took place smoothly under the influence of HBF4 in aqueous media to afford dihydro-4-pyridone derivatives in high yields.
Acid-Free Aza Diels−Alder Reaction of Danishefsky's Diene with Imines
作者:Yu Yuan、Xin Li、Kuiling Ding
DOI:10.1021/ol0265822
日期:2002.9.1
[reaction: see text] A highly efficient aza Diels-Alder reaction of Danishefsky'sdiene with imines was found to occur in methanol in the absence of any acids at room temperature to give corresponding 2-substituted dihydro-4-pyridone derivatives in high yields. This reaction can be also carried out in a three-component one-pot reaction manner. The reaction was found to proceed through a Mannich-type
1-Unsubstituted 4-dimethylamino-5,6-dihydropyridine-2(1H)-thiones were converted to isomeric piperidin-4-ols which were separated and N-methylated to 2-substituted 1-methylpiperidin-4-ols. Their 1-phenyl analogues were prepared from 4-dimethylamino-5,6-dihydro-1-phenylpyridine-2(1H)-thiones. After their conversion to dihydro-1-phenylpyridin-4(1H)-ones the hydrogenation gave isomeric 1-phenylpiperidin-4-ols