SmI2-Mediated Cross-Coupling of Nitrones with β-Silyl Acrylates: Synthesis of (+)-Australine
摘要:
The SmI2-mediated cross-coupling of nitrones with beta-silyl-alpha,beta-unsaturated esters, followed by zinc reduction, allows an efficient and highly diastereoselective preparation of beta-silyl lactams, which are precursors of beta-hydroxy lactams through Tamao-Fleming oxidation. By applying the method to a cyclic, carbohydrate-derived nitrone, a new synthesis of (+)-australine has been realized in only 11 steps and in 21% overall yield from L-xylose.
选择性糖基化:通过完全立体选择性硝酮环加成,Tamao-Fleming氧化和选择性α-葡萄糖基化为关键步骤,实现了天然木麻黄的全合成(1)和木麻黄的6 - O -α-葡萄糖苷的首次全合成(2)。两种化合物的生物学分析证明它们分别对葡糖淀粉酶NtMGAM和海藻糖酶Tre37A具有强大的选择性抑制特性,这使它们成为这些酶的最强抑制剂。
Activation of Si-Si Bonds for Copper(I)-Catalyzed Conjugate Silylation
作者:Laura Iannazzo、Gary A. Molander
DOI:10.1002/ejoc.201200767
日期:2012.9
silylation of α,β-unsaturated compounds. Optimal reaction conditions were first investigated to realize the conjugate addition of a nucleophilic silicon species to poorly electrophilic acceptors such as phenylvinyl sulfone by cleavage of the Si-Si bond of a disilane reagent. The scope of this reaction was extended to various electrophiles bearing different electron-withdrawing groups and afforded the
Total Syntheses of Casuarine and Its 6-<i>O</i>-α-Glucoside: Complementary Inhibition towards Glycoside Hydrolases of the GH31 and GH37 Families
作者:Francesca Cardona、Camilla Parmeggiani、Enrico Faggi、Claudia Bonaccini、Paola Gratteri、Lyann Sim、Tracey M. Gloster、Shirley Roberts、Gideon J. Davies、David R. Rose、Andrea Goti
DOI:10.1002/chem.200801578
日期:2009.2.2
Selective glucosylation: Total synthesis of naturally occurring casuarine (1) and the first total synthesis of casuarine 6‐O‐α‐glucoside (2) were achieved through complete stereoselective nitrone cycloaddition, Tamao–Fleming oxidation and selective α‐glucosylation as key steps. Biological assays of the two compounds proved their strong and selective inhibitory properties towards glucoamylase NtMGAM and
选择性糖基化:通过完全立体选择性硝酮环加成,Tamao-Fleming氧化和选择性α-葡萄糖基化为关键步骤,实现了天然木麻黄的全合成(1)和木麻黄的6 - O -α-葡萄糖苷的首次全合成(2)。两种化合物的生物学分析证明它们分别对葡糖淀粉酶NtMGAM和海藻糖酶Tre37A具有强大的选择性抑制特性,这使它们成为这些酶的最强抑制剂。
SmI<sub>2</sub>-Mediated Cross-Coupling of Nitrones with β-Silyl Acrylates: Synthesis of (+)-Australine
作者:Pierre Gilles、Sandrine Py
DOI:10.1021/ol203396s
日期:2012.2.17
The SmI2-mediated cross-coupling of nitrones with beta-silyl-alpha,beta-unsaturated esters, followed by zinc reduction, allows an efficient and highly diastereoselective preparation of beta-silyl lactams, which are precursors of beta-hydroxy lactams through Tamao-Fleming oxidation. By applying the method to a cyclic, carbohydrate-derived nitrone, a new synthesis of (+)-australine has been realized in only 11 steps and in 21% overall yield from L-xylose.