A general and practical method for the preparation of unsymmetrically substituted ureas has been developed. By the reactions of acetoacetanilides with various amines including primary/secondary amines, a series of substituted aryl ureas were achieved in high yields. Acetoacetanilide substrates can be considered as masked reagents that liberate reactive isocyanates in situ.
Efficient three-component one-pot synthesis of fully substituted pyridin-2(1H)-ones via tandem Knoevenagel condensation–ring-opening of cyclopropane–intramolecular cyclization
作者:Fushun Liang、Xin Cheng、Jing Liu、Qun Liu
DOI:10.1039/b905742k
日期:——
An efficientsynthesis of fully substituted pyridin-2(1H)-ones was developed via three-component one-pot reactions of readily available 1-acetyl-1-carbamoyl cyclopropanes, malononitrile and cyclic secondary amines.
Vilsmeier-Type Reaction of Dimethylaminoalkenoyl Cyclopropanes: One-Pot Access to 2,3-Dihydrofuro [3,2-<i>c</i>]pyridin-4(5<i>H</i>)-ones
作者:Peng Huang、Ning Zhang、Rui Zhang、Dewen Dong
DOI:10.1021/ol203124f
日期:2012.1.6
A dominoreaction of readily available 1-carbamoyl-1-dimethylaminoalkenoylcyclopropanes in the presence of triflic anhydride (Tf2O) in N,N-dimethylformamide (DMF) is described, which provides a facile one-pot access to 2,3-dihydrofuro[3,2-c]pyridin-4(5H)-ones via tandem formylation (Vilsmeier-type reaction), intramolecular cyclization, and ring-enlargement sequences.
描述了在三氟甲磺酸酐(Tf 2 O)存在下于N,N-二甲基甲酰胺(DMF)中容易获得的1-氨基甲酰基-1-二甲基氨基链烯酰基环丙烷的多米诺反应,该反应可轻松地一锅获得2,3-二氢呋喃[3,2 - c ] pyridin-4(5 H)-通过串联甲酰化反应(Vilsmeier型反应),分子内环化和环扩大序列。
PIFA/TEMPO‐Mediated Oxidative Cascade Cyclization of
<i>α</i>
‐[(
<i>β</i>
‐Amino)propenoyl]‐Alkylamides: Access to Polysubstituted 3,7‐Dihydrooxazolo[4,5‐
<i>c</i>
]pyridine‐2,4,6(5
<i>H</i>
)‐triones
bis(trifluoroacetate) (PIFA) and 2,2,6,6‐tetramethyl piperidin‐1‐oxyl (TEMPO) has been described. This unprecedented transformation features mild reaction conditions, simple execution, high chemo‐ and regio‐selectivity, and thereby provides a facile and efficient protocol for the synthesis of polysubstituted 3,7‐dihydro‐ oxazolo[4,5‐c]pyridine‐2,4,6‐(5H)‐triones.
苯基碘(III)双(三氟乙酸)(PIFA)和2,2,6,6-四甲基哌啶-1-氧基(TEMPO)介导的α -[[(β-氨基)丙烯酰基]-烷基酰胺的新型氧化级联环化已经描述过了。这种前所未有的转化具有温和的反应条件,简单的操作,较高的化学和区域选择性,从而为合成多取代的3,7-二氢恶唑[4,5 - c ]吡啶-2提供了简便而有效的方案, 4,6-(5 H)-三酮。
One-Pot Tandem Double-Aldol Reaction/Aza-Addition of Acetylacetamides and <i>o</i>-Phthalaldehyde Leading to Spiroindan-2,2′-pyrrolidines
作者:Xin Cheng、Fushun Liang、Fan Shi、Lei Zhang、Qun Liu
DOI:10.1021/ol802507y
日期:2009.1.1
A novel domino reaction based on o-phthalaldehyde and 3-oxo-N-arylbutanamide 1 has been developed which allows one-pot and efficient synthesis of structurally complex spiroindan-2,2'-pyrrolidines 2 and 3 with complete regioselectivity and high stereoselectivity from acyclic precursors.