Bond Activation and Catalysis by Main Group Systems

主要系统的键活化和催化

• 批准号: EP/L025000/1
• 负责人: Simon Aldridge
• 金额: $ 45.5万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FL025000%2F1
• 关键词: Bond; Activation; Catalysis; Main; Group

The activation of relatively inert non-polar chemical bonds is key to numerous catalytic functionalization processes generating high value-added chemical products. In the region of 75% of all chemicals currently require catalysts at some stage in their manufacture, and typical catalysts feature heavier late Transition Metals, reflecting their amenability to bond modifying redox processes. Issues relating to the sustainable availability/cost of such elements and the incorporation of heavy metals into products, mean that the search for alternative catalytic platforms is at the cutting edge scientifically and economically. Main Group metals, by contrast, are inexpensive, abundant, and in the cases of the lighter elements (such as the germanium compounds ultimately targeted here) less of an issue with regard to toxicity.In recent years, research into Main Group element compounds has highlighted the accessibility of low-valent derivatives with vacant coordination sites, and frontier orbitals with relatively small energy gaps able to facilitate bond activation by oxidative addition. Thus, a fundamental mode of reactivity typical of late Transition Metals has been opened up, and small molecule activation under mild conditions can be envisaged. Complementary strategies utilising redox inert metals (e.g. Ca2+) in constant oxidation state catalysis (e.g. via sigma-bond metathesis) have also emerged. Thus, the opportunity to exploit Main Group elements, once perceived as catalytically inert, as novel catalysts is not only at the cutting edge scientifically, but also offers huge potential for growth. With regard to redox-based processes, Main Group systems capable of effecting oxidative activation of E-H bonds are now known (e.g. for E = H, C, N, O, Si). Reagents capable of such insertion chemistry, however, are often highly reactive sub-valent species, and E-H bond activation processes typically generate products in thermodynamically very stable oxidation states. Catalytic turnover via reductive regeneration of the active species similar to late d-block catalysis is thus difficult to effect. However, our recent work and related research into Group 15 systems gives encouragement that catalytic cycles based on n/n+2 oxidation states for Main Group elements are indeed viable.The step change in homogenous catalysis which this proposal seeks to bring about is to open up catalytic bond modification processes based on redox chemistry (oxidative addition/reductive elimination) to Main Group metals. Our approach will be built on exciting preliminary results for tin systems, while ultimately targeting catalysts based around germanium, which is more environmentally benign, but a more challenging redox prospect. Our goals for the lifetime of this project are not necessarily to produce immediate replacements for existing Transition Metal systems in societally important catalytic transformations, but rather to establish the fundamental ground rules for catalyst design in what is an entirely new area of endeavour.

相对惰性的非极性化学键的活化是产生高附加值化学产品的许多催化功能化过程的关键。目前，在所有化学品的75%的区域中，在其制造的某个阶段需要催化剂，并且典型的催化剂具有较重的后过渡金属，反映了它们对键改性氧化还原过程的顺从性。与这些元素的可持续可用性/成本以及将重金属纳入产品有关的问题意味着寻找替代催化平台在科学和经济上处于最前沿。相比之下，主族金属价格低廉，储量丰富，（例如本文最终目标的锗化合物）毒性问题较小。近年来，对主族元素化合物的研究强调了具有空配位位点的低价衍生物的可及性，以及具有相对小的能隙的前线轨道，其能够通过氧化加成促进键活化。因此，后过渡金属典型的反应性的基本模式已经被打开，并且可以设想在温和条件下的小分子活化。还出现了在恒定氧化态催化中利用氧化还原惰性金属（例如Ca 2+）的互补策略（例如通过σ键复分解）。因此，利用曾经被认为是催化惰性的主族元素作为新型催化剂的机会不仅在科学上处于前沿，而且还提供了巨大的增长潜力。关于基于氧化还原的方法，现在已知能够实现E-H键的氧化活化的主族体系（例如对于E = H、C、N、O、Si）。然而，能够进行这种插入化学的试剂通常是高反应性的低价物质，并且E-H键活化过程通常产生化学上非常稳定的氧化态的产物。因此，通过类似于后期d-嵌段催化的活性物质的还原再生的催化周转难以实现。然而，我们最近的工作和相关的研究15族系统给人的鼓舞，催化循环的基础上n/n+2氧化态的主族元素确实是可行的。在均相催化的阶跃变化，这一建议试图带来的是开放的基础上氧化还原化学（氧化加成/还原消除）的主族金属的催化键修饰过程。我们的方法将建立在锡系统令人兴奋的初步结果的基础上，而最终目标是基于锗的催化剂，这是一种更环保，但更具挑战性的氧化还原前景。我们在这个项目的生命周期内的目标不一定是在社会重要的催化转化中生产现有过渡金属系统的直接替代品，而是在一个全新的努力领域建立催化剂设计的基本规则。

项目成果

Synthetic, structural and reaction chemistry of N-heterocyclic germylene and stannylene compounds featuring N-boryl substituents.

• DOI: 10.1039/c9dt02449b
• 发表时间: 2019-08
• 期刊: Dalton transactions
• 影响因子: 4
• 作者: Lilja Kristinsdóttir;Nicola L Oldroyd;Rachel Grabiner;Alastair W. Knights;A. Heilmann;A. Protchenko;Haoyu Niu;E. Kolychev;Jesús Campos;Jamie Hicks;K. Christensen;S. Aldridge

A ß-Diketiminate-Stabilized Sila-Acyl Chloride: Systematic Access to Base-Stabilized Silicon Analogues of Classical Carbonyl Compounds

A-二酮亚胺稳定的硅酰氯：系统获得经典羰基化合物的碱稳定的硅类似物

• DOI: 10.1002/ange.201807543
• 发表时间: 2018
• 期刊: Angewandte Chemie
• 作者: Do D

Highly Electron-Rich ß-Diketiminato Systems: Synthesis and Coordination Chemistry of Amino-Functionalized "N-nacnac" Ligands.

高度富含电子的 à-Diketiminato 系统：氨基官能化“N-nacnac”配体的合成和配位化学。

• DOI: 10.1002/chem.201700757
• 发表时间: 2017
• 期刊: Chemistry (Weinheim an der Bergstrasse, Germany)
• 作者: Do DCH

N-nacnac Stabilized Tetrelenes: Formation of an N,P-Heterocyclic Germylene via C-C Bond Insertion

• DOI: 10.1002/zaac.201800259
• 发表时间: 2018-11-15
• 期刊: ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
• 影响因子: 1.4
• 作者: Dinh Cao Huan Do;Protchenko, Andrey V.;Aldridge, Simon
• 通讯作者: Aldridge, Simon

Electronic Delocalization in Two and Three Dimensions: Differential Aggregation in Indium "Metalloid" Clusters

二维和三维电子离域：铟“类金属”簇中的差异聚集

• DOI: 10.1002/ange.201708496
• 发表时间: 2017
• 期刊: Angewandte Chemie
• 作者: Protchenko A