由丙二腈衍生的具有环状结构的化合物在制药领域至关重要。在此,我们开发了一种简便的合成方案,在温和且环保的条件下,使用 CBr 4作为光催化剂,通过光触发烷基化得到功能性丙二腈衍生物。以丰富的乙烯丙二腈与四氢呋喃为底物,通过形成新的CC键发生无金属偶联反应。该反应显示出广泛的范围,对各种官能团的耐受性和合理的产率。借助 DFT 计算进行的机理研究表明,这种反应采取了激进的途径。我们期望该协议成为无金属 C C 偶联反应的有用平台。
The first direct asymmetricvinylogousMannich (AVM) reaction of alpha,alpha-dicyanoolefins and N-Boc aldimines was described promoted by a simple chiral bifunctional thiourea-tertairy amine organocatalyst. The reaction was highlyefficient (S/C up to 1000) and regio-, stereoselective (generally >99% de, 96 to >99.5% ee) at room temperature for a broad array of substrates. Enantiomerically pure delta-amino
These precursors are easily accessible from aryl methyl ketones. Various functional groups like alkyl, aryl, nitrile, amine, aroyl and thiomethyl can be directly installed to the benzene ring. The one-pot approach for the construction of thiomethylated-benzene nucleus was also developed. The structure of the synthesized compound was confirmed by X-ray crystallography.
A new type of ketene dithioacetal, 2-(3,3-bis-methylsulfanyl-1-arylallylidene)malononitriles containing 1,4 and 1,6-Michael acceptors, were synthesized to study their reactivity for the synthesis of a new molecular entity. We report a [5 + 1] annulation strategy for the construction of multifunctional biaryls and p-teraryls by the selection of a suitable nucleophilic source. The reaction of p-nitrotoluene
“On Water” Direct Catalytic Vinylogous Aldol Reaction of Silyl Glyoxylates
作者:Hong Pan、Man-Yi Han、Pinhua Li、Lei Wang
DOI:10.1021/acs.joc.9b01945
日期:2019.11.1
The unique reactivity of water in the direct catalytic vinylogous aldolreaction of silyl glyoxylates is reported. With the hydrogen-bonding networks from water, the unfavorable homogeneous reactions in organic solvents were severely suppressed, and the "on water" relay chemistry for the vinylogous aldolreaction was realized in heterogeneous conditions (water as solvent), providing the desired α-hydroxysilanes
Asymmetric organocatalytic vinylogous Michael addition triggered triple-cascade reactions of 2-hydroxycinnamaldehydes and vinylogous nucleophiles: construction of benzofused oxabicyclo[3.3.1]nonane scaffolds
作者:Hui-Chun Wu、Chen Wang、Ying-Han Chen、Yan-Kai Liu
DOI:10.1039/d0cc07761e
日期:——
An organocatalytic vinylogous Michael addition triggered triple-cascade reaction has been developed. 2-Hydroxycinnamaldehydes worked under iminiumactivation with either acyclic or cyclic ketone-derived α,α-dicyanoalkenes, yielding the benzofused oxabicyclo[3.3.1]nonanes bearing one quaternary stereocenter with excellent stereoselectivities.