Generation of ditetrelynes by B-O bond elimation: bond activation and catalysis

本项目将研究在催化相关条件下，通过形成强E'-O键（E' = B, Al, Si）形成低价基团14化合物。然后将研究这些二苯乙烯对一系列有机和无机底物的还原键激活能力，并随后应用于催化转化。第一阶段：该项目最初将侧重于形成一系列terphenyl负载的二价14族烷氧化物，这些烷氧化物将作为预催化剂。有了这些物质，它们对E‘-E’物质的反应性将被定位为产生含有E(I)中心的LEEL （E = Ge, Sn; L = terphenyl）形式的物质。第二阶段：LEEL物质（E = Ge, Sn; L = terphenyl）对含有可还原片段的有机底物的反应性，如杂环烯、烯烃、羰基衍生物；小分子如H2、CO、乙烯和无机分子如磷氧化物、四价四萜和等构、等电子烯烃类似物如氨硼烷衍生物将被研究。第3阶段：利用经过验证的还原步骤和在催化相关条件下改造level物种的新方法，我们将研究上述底物的催化硼化还原。机械的洞察力将寻求通过标准的物理无机技术，以及operando光谱。这项工作将寻求验证低价主基团片段在氧化还原循环催化中的功效。这种机械的方法将是独一无二的，是当今主基团化学的“圣杯”之一。通过取代贵金属催化，对地球丰富和绿色催化剂的吸收具有深远的意义。这将有助于英国在精细化学品领域的世界领先地位。这项工作符合EPSRC对催化的持续兴趣。由于Ruth Webster博士在地球丰富金属催化领域的丰富经验，她将担任第二导师，并将在机理见解，新反应开发和反应性原位分析方面提供意见。

This project will investigate the formation of low-valent group 14 compounds under catalyticaly relevant conditions via the formation of strong E'-O bonds (E' = B, Al, Si). These ditetrelynes will then be investigated for their reductive bond activation capacity towards a range of organic and inorganic substrates and subsequently applied in catalytic transformations.Stage 1:The project will initially focus on the formation of a range of terphenyl supported divalent group 14 alkoxides which will act as precatalysts. With these species in hand their reactivity towards E'-E' species will be targeted to generate species of the form LEEL (E = Ge, Sn; L = terphenyl) which contain E(I) centres.Stage 2:The reactivity of LEEL species (E = Ge, Sn; L = terphenyl) towards organic substrates containing reducible fragments such as heterocumulenes, alkenes, carbonyl derivatives; small molecules such as H2, CO, ethene and inorganic molecules such as phosphine oxides, tetravalent tetrels and isosteric, isoelectronic alkene analogues such as ammonia borane derivates will be investigated.Stage 3:With validated reductive steps and new methodologies to reform LEEL species under catalytically relevant conditions in hand, we will investigate the catalytic borylative reduction of the aforementioned substrates. Mechanistic insight will be sought via standard physical inorganic techniques, as well as operando spectroscopy.This work will seek to validate the efficacy of low valent main group fragments in redox cycling for catalysis. Such a mechanistic approach would be unique and is one of the "holy grails" of main group chemistry today. The implications for the uptake of Earth abundant and green catalysis would be profound by replacing precious metal catalysis. This will contribute to Britain's world leading position in fine chemicals. This work fits within the EPSRC's ongoing interest in catalysis.Dr Ruth Webster will act as second supervisor as a result of her extensive experience in the area of Earth abundant metal catalysis and she will provide input on mechanistic insight, new reaction development and in situ analysis of reactivity.