Tandem Mn-I exchange and homocoupling processes mediated by a synergistically operative lithium manganate.

Tandem Mn-I exchange and homocoupling processes mediated by a synergistically operative lithium manganate.
Angew Chem Int Ed Engl. 2020 Oct 22;:
Authors: Hevia E, Uzelac M, Mastropierro P, De Tullio M, Borilovic I, Tarres M, Kennedy A, Aromi G
Abstract
Pairing lithium and manganese(II) to form lithium manganate [Li 2 Mn(CH 2 SiMe 3 ) 4 ] ( 2b ) enables the efficient direct Mn-I exchange of aryliodides, affording transient (aryl)lithium manganate intermediates which in turn undergo spontaneous C-C homocoupling at room temperature to furnish a range of symmetrical (bis)aryls in good yields under mild reaction conditions. Combining EPR with X-ray crystallographic studies light has been shone on the mixed Li/Mn constitution of the organometallic intermediates involved in these reactions, including the homocoupling step which had previously been thought to occur via single-metal Mn aryl species. These studies have illuminated how Li and Mn work together in a synergistic manner to facilitate both the Mn-I exchange and the C-C bond forming steps. Both steps are carefully synchronised, with the alkyliodide ICH 2 SiMe 3  concomitantly generated during the Mn-I exchange, being essential to enable the aryl homocoupling process by acting as an in-situ generated oxidant.
PMID: 33090640 [PubMed - as supplied by publisher]

Source: Angewandte Chemie - October 22, 2020 Category: Chemistry Authors: Hevia E, Uzelac M, Mastropierro P, De Tullio M, Borilovic I, Tarres M, Kennedy A, Aromi G Tags: Angew Chem Int Ed Engl Source Type: research