Synthesis ( IF 2.2 ) Pub Date : 2018-03-27 , DOI: 10.1055/s-0036-1591957 Vilius Franckevičius 1 , Miles Kenny 1 , Sybrin Schröder 2 , Nicholas Taylor 2 , Paula Jackson 2 , Daniel Kitson 1
|
Abstract
This article describes the palladium-catalysed three-component coupling of 1,3-dicarbonyl compounds with nucleophiles and propargylic electrophiles for the generation of quaternary all-carbon centres in a single step, which necessitates the simultaneous control of regio-, chemo- and enantioselectivity. The use of propargyl enol carbonates, the source of two of the components, was found to be essential in maintaining high levels of regiocontrol and chemoselectivity, whereas a careful analysis of pK a trends of O-, C- and N-nucleophiles as the other coupling partner indicates that the highest levels of selectivity are likely to be obtained with relatively acidic species, such as phenols, 1,3-dicarbonyl compounds and aromatic N-heterocycles. Finally, studies towards the development of the catalytic enantioselective construction of quaternary all-carbon centres by means of alkenylation and allylic alkylation are disclosed.
This article describes the palladium-catalysed three-component coupling of 1,3-dicarbonyl compounds with nucleophiles and propargylic electrophiles for the generation of quaternary all-carbon centres in a single step, which necessitates the simultaneous control of regio-, chemo- and enantioselectivity. The use of propargyl enol carbonates, the source of two of the components, was found to be essential in maintaining high levels of regiocontrol and chemoselectivity, whereas a careful analysis of pK a trends of O-, C- and N-nucleophiles as the other coupling partner indicates that the highest levels of selectivity are likely to be obtained with relatively acidic species, such as phenols, 1,3-dicarbonyl compounds and aromatic N-heterocycles. Finally, studies towards the development of the catalytic enantioselective construction of quaternary all-carbon centres by means of alkenylation and allylic alkylation are disclosed.
中文翻译：
钯催化亲电亲碳全碳四元中心的构建：区域，化学和对映体选择性同时控制中的挑战。
摘要
本文介绍了钯催化的1,3-二羰基化合物与亲核试剂和炔丙基亲电试剂的三组分偶联，可在一个步骤中生成季全碳中心，这需要同时控制区域，化学和对映选择性。发现使用炔丙基碳酸酯（两种成分的来源）对于维持高水平的区域控制和化学选择性至关重要，而仔细分析p K aO-，C-和N-亲核试剂作为其他偶联伴侣的趋势表明，使用相对酸性的物质（例如苯酚，1,3-二羰基化合物和芳族N-杂环）可能会获得最高的选择性。最后，公开了对通过烯基化和烯丙基烷基化发展季全碳中心的催化对映选择性结构的研究。
本文介绍了钯催化的1,3-二羰基化合物与亲核试剂和炔丙基亲电试剂的三组分偶联，可在一个步骤中生成季全碳中心，这需要同时控制区域，化学和对映选择性。发现使用炔丙基碳酸酯（两种成分的来源）对于维持高水平的区域控制和化学选择性至关重要，而仔细分析p K aO-，C-和N-亲核试剂作为其他偶联伴侣的趋势表明，使用相对酸性的物质（例如苯酚，1,3-二羰基化合物和芳族N-杂环）可能会获得最高的选择性。最后，公开了对通过烯基化和烯丙基烷基化发展季全碳中心的催化对映选择性结构的研究。
京公网安备 11010802027423号