Interplay between stable carbenes and neutral group-13 element nucleophiles, organic radicals, and strong bases

在这个由化学系化学结构、动态和机理B计划资助的项目中，加州大学圣地亚哥分校(UCSD)化学和生物化学系的Guy Bertrand教授将为过渡金属催化剂和新的稳定自由基制备原始配体。需要富电子配体的无数催化应用将受益于将被合成的第13族元素物种。自由基参与了许多化学和生物过程，它们的稳定将使人们能够更好地了解它们的性质。该项目处于物理化学、有机化学、无机化学和有机金属化学的交界处，因此非常适合各级科学家的教育。首席研究员的实验室是加州大学可持续发展分校和法国国家科学研究中心的合资企业。它的作用是促进加州大学和欧洲大学之间的本科生和毕业生的交流。多年来，过渡金属催化剂的“定向L”配体是基于第15和第16族元素。N-杂环卡宾的引入，以及因此基于第14族元素的辅助配体的引入，已经产生了许多突破。这是由于卡宾具有很强的西格玛施主性质，这是由于碳的电负性比第15和16族元素低。配体与胺和卡宾是等电子的，但基于B、Al和Ga，它们的电负性甚至比C更小，将是非常强的电子给体配体。亲电性稳定的卡宾也将用于制备稳定的有机自由基和多自由基。由于自由基的稳定性，一个应用将是发现有效的、无毒的氢供体。最后，从新发现的非亲电的介离子卡宾衍生的亚胺和叶立德取代基将被用于制备强中性碱和氢化物给体。

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Guy Bertrand of the Chemistry and Biochemistry Department at the University of California - San Diego (UCSD), will prepare original ligands for transition metal catalysts and novel stable radicals. The myriad of catalytic applications requiring electron-rich ligands will benefit from the group 13 element species that will be synthesized. Radicals are involved in numerous chemical and biological processes, and their stabilization will allow for a better understanding of their properties. This project is at the interface between physical, organic, inorganic and organometallic chemistry; therefore it is well suited to the education of scientists at all levels. The laboratory of the principal investigator is a joint venture between UCSD and the French National Centre for Scientific Research. It serves to promote the exchange of undergraduates and graduates between UCSD and European Universities.For years the "directing L" ligands of transition metal catalysts were based on the elements of groups 15 and 16. The introduction of N-Heterocyclic Carbenes, and thus of ancillary ligands based on a group 14 element, has generated many breakthroughs. This is the result of the strong sigma-donor properties of carbenes, which are due to the lower electronegativity of carbon compared to group 15 and 16 elements. Ligands, which are isoelectronic with amines and carbenes, but based on B, Al and Ga that are even less electronegative than C, will be extremely strong electron-donor ligands. Electrophilic stable carbenes will also be used for preparing stable organic radicals and polyradicals. An application, resulting from the stability of radicals, will be the discovery of efficient, non-toxic, hydrogen donors. Lastly iminato and ylide substituents, derived from the newly discovered non-electrophilic mesoionic carbenes, will be used for the preparation of strong neutral bases and hydride donors.