2026-09-20T03:03:02Zhttps://helda.helsinki.fi/server/oai/request

oai:helda.helsinki.fi:10138/3385212026-07-23T15:16:00Zcom_10138_18086com_10138_17738col_10138_18093

Helsingin yliopisto, Matemaattis-luonnontieteellinen tiedekunta University of Helsinki, Faculty of Science Helsingfors universitet, Matematisk-naturvetenskapliga fakulteten Puumi, Jukka 2021 URN:NBN:fi:hulib-202201121022 http://hdl.handle.net/10138/338521 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. eng Helsingin yliopisto University of Helsinki Helsingfors universitet Nickel Ni photocatalysis photocatalyst PC Cross-coupling Mechanism EnT SET PET Kemia Chemistry Kemi Kemian ja molekyylitieteiden maisteriohjelma Master's Programme in Chemistry and Molecular Sciences Magisterprogrammet i kemi och molekylära vetenskaper ARYL-HETEROATOM CROSS-COUPLING WITH DUAL NICKEL/PHOTOCATALYST PROTOCOLS : THEORY, APPLICATIONS AND RECENT DEVELOPMENTS pro gradu -tutkielmat master's thesis pro gradu-avhandlingar URN:NBN:fi:hulib-202201121022 open.access