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14族化合物。然后将研究这些二叔丁炔类化合物对一系列有机和无机底物的还原活化能力，并随后应用于催化转化。第一阶段：项目最初将专注于形成一系列三苯基支撑的二价基14烷氧基化合物，这些化合物将作为前催化剂。有了这些物种，它们对E‘-E’物种的反应性将被瞄准以生成含有E(I)中心的形式的LEL(E=Ge，Sn；L=三苯基)的物种。阶段2：LEL物种(E=Ge，Sn；L=三苯基)对含有可还原片段的有机底物的反应，所述有机底物含有可还原的碎片，例如杂聚丁烯、烯烃、羰基衍生物；将研究小分子如H2、CO、乙烯和无机分子如膦氧化物、四价四氢化合物和等空间、等电子的烯烃类似物如氨硼烷衍生物。阶段3：通过已证实的还原步骤和在催化相关条件下改造LEL物种的新方法，我们将研究上述底物的催化硼化还原。这项工作将通过标准的物理无机技术以及操纵道光谱来寻求机理上的洞察力。这项工作将寻求验证低价主族片段在氧化还原循环催化中的有效性。这种机械论的方法是独一无二的，是当今主族化学的“圣杯”之一。通过取代贵金属催化，对吸收地球丰富和绿色催化的影响将是深远的。这将有助于英国在精细化学品领域保持世界领先地位。这项工作符合EPSRC对催化剂的持续兴趣。Ruth Webster博士将担任第二主管，因为她在地球丰富的金属催化领域拥有丰富的经验，她将在机理洞察、新的反应开发和反应性的现场分析方面提供意见。

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.