Gold-Catalyzed Synthesis of Alkylidene 2-Oxazolidinones and 1,3-Oxazin-2-ones
摘要:
N-Boc-protected alkynylamines are converted into the corresponding alkylidene 2-oxazolidinones or 2-oxazinones under very mild reaction conditions in the presence of 1-5 mol% of a cationic Au(I) complex. The scope of the reaction is very general, providing the cyclic carbamates in high yield regardless of the substitution at nitrogen and alkyne terminus.
Gold-Catalyzed Synthesis of Alkylidene 2-Oxazolidinones and 1,3-Oxazin-2-ones
作者:Rocío Robles-Machín、Javier Adrio、Juan Carlos Carretero
DOI:10.1021/jo060520y
日期:2006.6.1
N-Boc-protected alkynylamines are converted into the corresponding alkylidene 2-oxazolidinones or 2-oxazinones under very mild reaction conditions in the presence of 1-5 mol% of a cationic Au(I) complex. The scope of the reaction is very general, providing the cyclic carbamates in high yield regardless of the substitution at nitrogen and alkyne terminus.
An expedient copper-catalysed asymmetric synthesis of γ-lactones and γ-lactams. Application to the synthesis of lucidulactone A
作者:O. Stephen Ojo、David L. Hughes、Christopher J. Richards
DOI:10.1039/d3ob00563a
日期:——
The parent Josiphos ligand gave excellent ee values (95–99%) and good yields (60–97%) in the copper-catalysed asymmetric conjugate reduction of β-aryl α,β-unsaturated lactones and lactams with PMHS. The substrates were obtained from stereospecific copper-catalysed addition of arylboronic acids to alkynoates followed by deprotection and cyclisation. The acyclic lactam precursors also underwent reduction
母体 Josiphos 配体在铜催化的 β-芳基 α,β-不饱和内酯和内酰胺与 PMHS 的不对称共轭还原反应中具有优异的 ee 值 (95–99%) 和良好的产率 (60–97%)。底物是通过铜催化的立体定向加成将芳基硼酸加成炔酸酯,然后脱保护和环化获得的。无环内酰胺前体也经历了还原,具有良好的 ee 值 (83–85%) 和收率 (79–95%)。这种不对称还原方法的应用包括天然产物 lucidulactone A 的合成。