ARYL-HETEROATOM CROSS-COUPLING WITH DUAL NICKEL/PHOTOCATALYST PROTOCOLS : THEORY, APPLICATIONS AND RECENT DEVELOPMENTS

An overview on utilization of dual nickel/photocatalyst protocols to conduct aryl-heteroatom cross-coupling reactions is presented. Basic concepts of photocatalysis, including different relaxation pathways, the difference of singlet and triplet states, and parameters used to predict reactivity are first disclosed. The general components used in dual nickel/photocatalyst protocols are presented followed by the discussion on reactivity trends. The reactivity trends are compared with other common aryl-heteroatom cross-coupling protocols (Buchwald-Hartwig-, Ullmann- and Chan-Lam couplings) illustrating the general advantages and disadvantages of each cross-coupling method. The scope of different dual nickel/photocatalyst protocols are then explored, concentrating on cross-coupling of amines, alcohols/thiols and carboxylic acids. The developments in mechanistic understanding on the dual nickel/photocatalyst aryl-heteroatom cross-couplings in recent years are reviewed. It is concluded that photocatalytic single electron transfer-based cycles, proposed for a number of coupling protocols, are very unlikely to take place. It is made clear that, based on the current knowledge, two principle mechanism are reasonable: energy transfer or thermal Ni(I)/Ni(III) cycles. Problems concerning energy transfer mechanisms are also discussed. Finally, applicability of dual nickel/photocatalyst aryl-heteroatom cross-coupling for industrially significant transformations is briefly discussed.

Grantor dc:publisher

Helsingin yliopisto

Year dc:date.issued

2021

Author dc:creator

• Puumi, Jukka

Contributors dc:contributor

• Helsingin yliopisto, Matemaattis-luonnontieteellinen tiedekunta
• University of Helsinki, Faculty of Science
• Helsingfors universitet, Matematisk-naturvetenskapliga fakulteten

• Nickel
• Ni
• photocatalysis
• photocatalyst
• PC
• Cross-coupling
• Mechanism
• EnT
• SET
• PET

Language dc:language.iso

eng

Identifier URI

URN:NBN:fi:hulib-202201121022

OAI identifier oai:identifier

oai:helda.helsinki.fi:10138/338521