已开发出一种适用于Knoevenagel化学的新的级联途径,该途径涉及1,3-二羰基体系与α,β,γ,δ-不饱和醛之间的偶联。该过程包括经典的醛醇缩合和罕见的无自发的无金属环异构化的组合,代表了环戊并[ b ]呋喃型衍生物的立体选择性合成的融合和创新方法。研究了反应伙伴和机理特征的范围和局限性。有意义的是,我们的研究为控制共轭多烯羰基体系反应性的结构和电子效应提供了有价值的指导。
Synthesis of δ-Tributylstannyl-α,β,γ,δ-Unsaturated Aldehydes from Pyridines
作者:Theo D. Michels、Jong Uk Rhee、Christopher D. Vanderwal
DOI:10.1021/ol8020435
日期:2008.11.6
Zincke aldehydes, which are readily available from the ring-opening reaction of pyridinium salts, are easily converted into delta-tributylstannyl-alpha,beta,gamma,delta-unsaturated aldehydes (stannyldienals) by the action of tributylstannyllithium. This reaction appears to proceed via 1,6-stannyllithium addition/elimination of lithium dialkylamide. Several stannyldienals of significant utility for
Metal- and Hydride-Free Pentannulative Reductive Aldol Reaction
作者:Bishnupada Satpathi、Lona Dutta、S. S. V. Ramasastry
DOI:10.1021/acs.orglett.8b03658
日期:2019.1.4
Traditionally, the reductivealdolreaction is a metal-catalyzed and hydride-promoted coupling between enones and aldehydes. We present a phosphine-mediated diastereoselective intramolecular reductivealdolreaction of α-substituted dienones and aldehydes, which is metal-free and hydride-free. The synthetic utility of the reductivealdol adducts is demonstrated by elaborating them in one step to indeno[1
传统上,还原性醇醛缩合反应是烯酮和醛之间的金属催化和氢化物促进的偶联。我们提出了一种α-取代的二烯酮和醛的膦介导的非对映选择性分子内还原醛醇缩合反应,该反应不含金属且不含氢化物。还原性羟醛加合物的合成效用通过一步一步将它们合成为茚并[1,2- b ]呋喃酮,茚并[1,2- b ]吡喃和二苯并[ a,h ] azulen -8-ones而得到证明。
Phosphine- and water-promoted pentannulative aldol reaction
作者:Bishnupada Satpathi、Lona Dutta、S. S. V. Ramasastry
DOI:10.1039/c8ob03106a
日期:——
intramolecular aldolreaction for the synthesis of an unusual class of cyclopentanoids is described. The reaction of α-substituted dienones tethered with ketones in the presence of tributylphosphine and water provided aldols. The role of water was realised to be crucial for this transformation. Furthermore, isotopic labeling experiments provided vital information about the reaction mechanism.
Iodine-Catalyzed Iso-Nazarov Cyclization of Conjugated Dienals for the Synthesis of 2-Cyclopentenones
作者:Lucía A. Marsili、Jorgelina L. Pergomet、Vincent Gandon、Martín J. Riveira
DOI:10.1021/acs.orglett.8b03229
日期:2018.11.16
Molecular iodine was identified as an efficient catalyst for the cycloisomerization of conjugated dienals to substituted 2-cyclopentenones. DFT calculations suggested an unexpected concerted character for this cyclization.
One-Pot Organocatalytic Tandem Aldol/Polycyclization Reactions between 1,3-Dicarbonyl Compounds and α,β,γ,δ-Unsaturated Aldehydes for the Straightforward Assembly of Cyclopenta[b]furan-Type Derivatives: New Insight into the Knoevenagel Reaction
作者:Martín J. Riveira、Mirta P. Mischne
DOI:10.1002/chem.201103080
日期:2012.2.20
chemistry that involves the coupling between 1,3‐dicarbonyl systems and α,β,γ,δ‐unsaturated aldehydes has been developed. The process comprises the combination of a classic aldol‐type condensation and a rare spontaneous metal‐free cycloisomerization, representing a convergent and innovative approach for the stereoselectivesynthesis of cyclopenta[b]furan‐type derivatives. The scope and limitations with
已开发出一种适用于Knoevenagel化学的新的级联途径,该途径涉及1,3-二羰基体系与α,β,γ,δ-不饱和醛之间的偶联。该过程包括经典的醛醇缩合和罕见的无自发的无金属环异构化的组合,代表了环戊并[ b ]呋喃型衍生物的立体选择性合成的融合和创新方法。研究了反应伙伴和机理特征的范围和局限性。有意义的是,我们的研究为控制共轭多烯羰基体系反应性的结构和电子效应提供了有价值的指导。