Micelle‐Mediated Trimerization of Ynals to Orthogonally Substituted 4
H
‐Pyrans in Water: Downstream Rearrangement to Bioactive 2,8‐dioxabicyclo[3.3.1]nona‐3,6‐diene Frameworks
摘要:
AbstractAn efficient trimerization of ynals to diversely substituted 4H‐pyran constructs has been executed in water, under ambient conditions employing micellar catalysis. The method is in agreement with the ideas of green and sustainable chemistry. The locus of the micellar reaction site has been probed through proton NMR studies. A general acid‐mediated downstream rearrangement of the derived 4H‐pyrans to interesting 2,8‐dioxabicyclo[3.3.1]nona‐3,6‐dienes has been observed.
Asymmetric Mannich Reaction of Dicarbonyl Compounds with α-Amido Sulfones Catalyzed by Cinchona Alkaloids and Synthesis of Chiral Dihydropyrimidones
作者:Sha Lou、Peng Dai、Scott E. Schaus
DOI:10.1021/jo701777g
日期:2007.12.1
The highly enantioselective cinchona alkaloid-catalyzed Mannich reaction of dicarbonyl compounds with α-amidosulfones as acyl imine precursors is described. The reaction requires 10 mol % of the cinchona alkaloid catalyst, which serves as a general base to generate acyl imines in situ, and aqueous Na2CO3 to maintain the concentration of free alkaloid catalyst. The reaction products are obtained in
描述了二羰基化合物与α-酰胺基砜作为酰基亚胺前体的高度对映选择性金鸡纳生物碱催化的曼尼希反应。该反应需要10 mol%的金鸡纳生物碱催化剂和Na 2 CO 3水溶液,该催化剂可作为一般的碱在现场生成酰基亚胺。保持游离生物碱催化剂的浓度。以高收率和高对映选择性以及从1∶1至> 95∶5的非对映选择性获得反应产物。辛可宁催化的反应提供了高度实用的结构单元的实际途径,该结构单元已用于手性二氢嘧啶酮的合成,手性二氢嘧啶酮是一类具有多种生物活性的化合物。二氢嘧啶酮修饰包括使用H-Cube流动氢化器和Rh(II)介导的1,3-偶极环加成反应对烯酰胺部分进行高度非对映选择性氢化,以提供高度官能化的复杂杂环。
WO2006/125276
申请人:——
公开号:——
公开(公告)日:——
Micelle‐Mediated Trimerization of Ynals to Orthogonally Substituted 4
<i>H</i>
‐Pyrans in Water: Downstream Rearrangement to Bioactive 2,8‐dioxabicyclo[3.3.1]nona‐3,6‐diene Frameworks
作者:Showkat Rashid、Bilal A. Bhat、Goverdhan Mehta
DOI:10.1002/ejoc.202101122
日期:2021.12.28
AbstractAn efficient trimerization of ynals to diversely substituted 4H‐pyran constructs has been executed in water, under ambient conditions employing micellar catalysis. The method is in agreement with the ideas of green and sustainable chemistry. The locus of the micellar reaction site has been probed through proton NMR studies. A general acid‐mediated downstream rearrangement of the derived 4H‐pyrans to interesting 2,8‐dioxabicyclo[3.3.1]nona‐3,6‐dienes has been observed.