Michael North

Bio: Michael North is an academic researcher from University of York. The author has contributed to research in topics: Catalysis & Enantioselective synthesis. The author has an hindex of 46, co-authored 223 publications receiving 7945 citations. Previous affiliations of Michael North include King's College London & Newcastle University.

Mechanism of Cyclic Carbonate Synthesis from Epoxides and CO2

Abstract: Three interconnected catalytic cycles account for the title reaction catalyzed by a bimetallic aluminum(salen) complex and Bu(4)NBr. In the first, Bu(4)NBr acts as a nucleophile to activate the epoxide. In the second, Bu(3)N generated in situ serves to activate CO(2). In the third, the aluminum(salen) complex brings the two activated species together so that the key bonds can be formed intramolecularly.

Cyclic Carbonate Synthesis Catalysed by Bimetallic Aluminium-Salen Complexes

Abstract: The development of bimetallic aluminium-salen complexes [{A1-(salen)} 2 O] as catalysts for the synthesis of cyclic carbonates (including the commercially important ethylene and propylene carbonates) from a wide range of terminal epoxides in the presence of tetrabutylammonium bromide as a cocatalyst is reported. The bimetallic structure of one complex was confirmed by X-ray crystallography. The bimetallic complexes displayed exceptionally high catalytic activity and in the presence of tetrabutylammonium bromide could catalyse cyclic carbonate synthesis at atmospheric pressure and room temperature. Catalyst-reuse experiments demonstrated that one bimetallic complex was stable for over 60 reactions, though the tetrabutylammonium bromide decomposed in situ by a retro-Menschutkin reaction to form tributylamine and had to be regularly replaced. The mild reaction conditions allowed a full analysis of the reaction kinetics to be carried out and this showed that the reaction was first order in aluminium complex concentration, first order in epoxide concentration, first order in carbon dioxide concentration (except when used in excess) and unexpectedly second order in tetrabutylammonium bromide concentration. Further kinetic experiments demonstrated that the tributylamine formed in situ was involved in the catalysis and that addition of butyl bromide to reconvert the tributylamine into tetrabutylammonium bromide resulted in inhibition of the reaction. The reaction kinetics also indicated that no kinetic resolution of racemic epoxides was possible with this class of catalysts, even when the catalyst was derived from a chiral salen ligand. However, it was shown that if enantiomerically pure styrene oxide was used as substrate, then enantiomerically pure styrene carbonate was formed. On the basis of the kinetic and other experimental data, a catalytic cycle that explains why the bimetallic complexes display such high catalytic activity has been developed.

Lewis acid catalyzed asymmetric cyanohydrin synthesis.

Abstract: 2.5. Aluminum-Based Catalytic Systems 5196 2.5.1. Complexes of C1-Symmetric Schiff Bases 5196 2.5.2. Complexes of C2-Symmetric Schiff Bases 5196 2.5.3. Complexes of BINOL-Based Ligands 5197 2.5.4. Complexes of Other C2-Symmetric Ligands 5202 2.5.5. Bifunctional Catalysts 5203 2.6. Tin-Based Catalytic Systems 5204 2.7. Magnesium-Based Catalytic Systems 5204 2.8. Yttrium-Based Catalytic Systems 5204 2.9. Lanthanide-Based Catalytic Systems 5206 2.10. Manganese-Based Catalytic Systems 5208 2.11. Bismuth-Based Catalytic System 5209 2.12. Zirconium-Based Catalytic Systems 5209 2.13. Cobalt-Based Catalytic Systems 5209 2.14. Group One Metal-Based Catalytic Systems 5210 2.15. Rhenium-Based Systems 5211 3. Chiral Lewis Acid-Based Systems for the Asymmetric Cyanation of Ketones 5212 3.1. Boron-Based Catalytic Systems 5212 3.2. Titanium-Based Catalytic Systems 5212 3.3. Aluminum-Based Catalytic Systems 5216 3.4. Lanthanide-Based Catalytic Systems 5217 3.5. Manganese-Based Catalytic Systems 5220 3.6. Sodium-Based Catalytic Systems 5220 4. Conclusions 5221 5. Note Added in Proof 5221 6. References 5222

Engineering Metal Organic Frameworks for Heterogeneous Catalysis

Abstract: 2.2. MOFs with Metal Active Sites 4614 2.2.1. Early Studies 4614 2.2.2. Hydrogenation Reactions 4618 2.2.3. Oxidation of Organic Substrates 4620 2.2.4. CO Oxidation to CO2 4626 2.2.5. Phototocatalysis by MOFs 4627 2.2.6. Carbonyl Cyanosilylation 4630 2.2.7. Hydrodesulfurization 4631 2.2.8. Other Reactions 4632 2.3. MOFs with Reactive Functional Groups 4634 2.4. MOFs as Host Matrices or Nanometric Reaction Cavities 4636

Carbon capture and storage (CCS): the way forward

Abstract: Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets, delivering low carbon heat and power, decarbonising industry and, more recently, its ability to facilitate the net removal of CO2 from the atmosphere. However, despite this broad consensus and its technical maturity, CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus, in this paper we review the current state-of-the-art of CO2 capture, transport, utilisation and storage from a multi-scale perspective, moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C, we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS), and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS, we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas, we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.

Metal–Salen Schiff base complexes in catalysis: practical aspects

Abstract: Schiff base ligands are considered “privileged ligands” because they are easily prepared by the condensation between aldehydes and imines. Stereogenic centres or other elements of chirality (planes, axes) can be introduced in the synthetic design. Schiff base ligands are able to coordinate many different metals, and to stabilize them in various oxidation states, enabling the use of Schiff base metal complexes for a large variety of useful catalytic transformations. Practical guidelines for the preparation and use of different Schiff base metal complexes in the field of catalytic transformations are discussed in this tutorial review.

Using carbon dioxide as a building block in organic synthesis

Abstract: Carbon dioxide exits in the atmosphere and is produced by the combustion of fossil fuels, the fermentation of sugars and the respiration of all living organisms. An active goal in organic synthesis is to take this carbon--trapped in a waste product--and re-use it to build useful chemicals. Recent advances in organometallic chemistry and catalysis provide effective means for the chemical transformation of CO₂ and its incorporation into synthetic organic molecules under mild conditions. Such a use of carbon dioxide as a renewable one-carbon (C1) building block in organic synthesis could contribute to a more sustainable use of resources.