Zinc Atom Transfer-Based Silylzincation of Alkynes

基于锌原子转移的炔烃的甲硅烷基锌化

• 批准号: 208581294
• 负责人: Professor Dr. Martin Oestreich
• 金额: --
• 依托单位: Institut Parisien de Chimie Moléculaire (IPCM)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/208581294?language=en
• 关键词: Zinc; Atom; Transfer; Based; Silylzincation

As part of the current interest in "step-economical" processes to progress towards sustainable chemical synthesis, we wish to develop a new radical-based entry to the silylzincation of alkynes. Inexpensive, non-toxic and with high functional group tolerance, organozincs have regained considerable interest from the chemical community as reagents of choice to develop more selective reactions. A specific feature of alkylzincs is that they can react either as polar nucleophiles (carbanions) or transfer homolytically a zinc group (zinc atom radical transfer) to an alkyl radical. The possibility to combine both types of reactivity in a single reaction has made possible recent multi-component radicalbased approaches to the carbozincation of alkenes and alkynes. Following the same strategy, we envision an approach to the silylzincation of alkynes based on a process wherein a silyl radical would add to a carbon-carbon triple bond to produce a vinylic radical that would be reductively zincated by undergoing a zinc atom radical transfer. The dimetallic 1,2-silylzinc species thus produced are expected to be well suited for in-situ functionalization. In a first research axis we will consider the use of silylzinc reagents. The preparation of new silylzinc reagents having silyl substituted silicon units and the study of their aptitude to transfer homolytically a zinc group will be studied prior to considering inter- and intramolecular additions to alkynes. In a second axis, silylzincation reactions using a combination of a silyl radical precursor and a dialkylzinc reagent will be explored, focusing mainly on intramolecular transformations. Finally, in a third part of the project, the use of 1-silyl-2-zincio alkenes as partners in sequential carbon-carbon bond forming metal-catalyzed crosscoupling reactions will be explored.

作为目前对“分步经济”方法的兴趣的一部分，以实现可持续的化学合成，我们希望开发一种新的基于自由基的炔的甲硅烷基锌化方法。廉价、无毒和具有高官能团耐受性的有机锌作为开发更选择性的反应的选择性试剂重新获得了化学界的相当大的兴趣。烷基锌的一个具体特征是它们可以作为极性亲核试剂（碳负离子）反应或将锌基团均裂转移（锌原子自由基转移）到烷基。在单一反应中联合收割机结合两种类型的反应性的可能性使得最近的基于多组分自由基的烯烃和炔的碳锌化方法成为可能。遵循相同的策略，我们设想了一种基于以下方法的炔的甲硅烷基锌化的方法，其中甲硅烷基基团将添加到碳-碳三键以产生乙烯基基团，该乙烯基基团将通过经历锌原子基团转移而被还原性锌化。由此产生的双金属1，2-甲硅烷基锌物质预期非常适合于原位官能化。在第一研究轴中，我们将考虑使用甲硅烷基锌试剂。制备新的甲硅烷基锌试剂具有甲硅烷基取代的硅单元和他们的能力转移均聚锌基团的研究将研究之前，考虑分子间和分子内添加到炔。在第二个轴，使用甲硅烷基自由基前体和二烷基锌试剂的组合的甲硅烷基锌化反应将被探索，主要集中在分子内的转换。最后，在该项目的第三部分中，将探索使用1-甲硅烷基-2-锌烯作为连续碳-碳键形成金属催化的交联反应的伙伴。