Synthesis 2021; 53(19): 3555-3563
DOI: 10.1055/a-1485-4956
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Tetrahydroxydiboron-Initiated Atom-Transfer Radical Cyclization

Pengfei Wang
,
Yuli Li
,
Guangwei Wang
The authors are grateful for the financial support from the Major National Science and Technology Projects of water pollution control and treatment (2017ZX07402003). The authors also thank the Natural Science Foundation of Tianjin (19JCYBJC20200) for support of this research.


Abstract

In this work, the first diboron reagent initiated atom-transfer radical cyclization was reported, in which the boryl radicals were generated by the homolytic cleavage of a B–B single bond weakened by the coordination of Lewis base. To clarify the role of carbonate and DMF in the cleavage of B–B bond, we calculated the free energy diagram of two pathways by density functional theory (DFT) investigations. The DFT calculation showed that the presence of carbonate facilitates the B–B bond cleavage to form boron radicals, which can be further stabilized by DMF. Subsequent atom-transfer cyclization initiated by stabilized dihydroxyboron radical is also energetically favored.

Supporting Information



Publication History

Received: 01 March 2021

Accepted after revision: 19 April 2021

Accepted Manuscript online:
19 April 2021

Article published online:
26 May 2021

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