通过简单有效的方法,实现了由辛可宁衍生的生物碱β-异cupreidine催化的N -2,2,2-三氟乙基异丁酮酮与MBH型碳酸盐之间的不对称S N 2'–S N 2'反应。制备了一系列具有优异收率和立体选择性的手性α-三氟甲基胺。随后且容易的脱保护过程以立体选择性的方式得到了γ-三氟甲基-α-亚甲基内酰胺。
The peroxy-asymmetric allylic alkylation of hydroperoxyalkanes with Morita–Baylis–Hillmancarbonates was catalysed by modifiedcinchonaalkaloids (up to 93% ee), from which chiral α-methylene-β-hydroxy esters could be efficiently derived.
A LewisbaseassistedBrønstedbasecatalysis (LBABB) strategy is applied for directasymmetric vinylogous alkylation of allylic sulfones with Morita–Baylis–Hillman (MBH) carbonates, in which a strong Brønstedbase, tert‐butoxy anion, generated in situ from a tertiary amine catalyst and MBH carbonate, is crucial in activating unstabilized nucleophiles. The γ‐regioselective alkylation products were
Vinylogous Nucleophiles Bearing the Endocyclic Double Bond in the Allylic Alkylation with Morita-Baylis-Hillman Carbonates
作者:Dorota Kowalczyk、Łukasz Albrecht
DOI:10.1002/adsc.201701185
日期:2018.2.1
nucleophilicity in the allylic alkylation with Morita‐Baylis‐Hillman carbonates can be accomplished through the endocyclic double bond in 3‐cyano‐4‐methylcoumarins. The developed reaction provides a straightforward access to functionalized coumarin derivatives of biological and synthetic relevance. Target, highly functionalized products have been chemoselectively and efficiently obtained in very high yield
A direct, asymmetricallylicalkylation of indenes withMorita–Baylis–Hillman (MBH) carbonates has been developed based on a Lewisbaseassisted Bronsted basecatalysis strategy. This process is promoted by a modified cinchona alkaloid hydroquinidine (anthraquinone-1,4-diyl) diether [(DHQD)2AQN] and gives rise to multifunctional chiral indene derivatives with moderate to excellent enantioselectivities
Allylic–Allylic Alkylation with 3,5-Dimethyl-4-nitroisoxazole: A Route to Dicarboxylic Acid Derivatives
作者:Dorota Kowalczyk-Dworak、Marcin Kwit、Łukasz Albrecht
DOI:10.1021/acs.joc.9b02530
日期:2020.3.6
In this work, the first application of 3,5-dimethyl-4-nitroisoxazole as a vinylogous pronucleophile in the allylic-allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates is described. The reaction has been realized under nucleophilic catalysis conditions with dimeric cinchona alkaloids, providing excellent enantiocontrol of the process. The usefulness of the products thus obtained has been confirmed