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Abstract Our efforts in the chemistry of gold complexes featuring ambiphilic phosphine‐carbenium L/Z‐type ligand have led us to consider the reduction of the carbenium moiety as a means to modulate the gold–carbenium interaction present in these complexes. Here, it was shown that the one‐electron reduction of [(o‐Ph2P(C6H4)Acr)AuCl]+(Acr=9‐N‐methylacridinium) produces a neutral stable radical, the structure of which showed a marked increase in the Au–Acr distance. Related structural changes were observed for the phosphine oxide analogue [(o‐Ph2P(O)(C6H4)Acr]+, the reduction of which interfered with the P=O→carbenium interaction. These structural effects, driven by a reduction‐induced change in the electronic and electrostatic characteristics of the compounds, showed that the charge and accepting properties of the carbenium unit can be modulated. These results highlight the redox‐noninnocence of carbenium Z‐type ligand, a feature that can be exploited to induce specific conformational changes.
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Accessing Ambiphilic Phosphine Boronates through C−H Borylation by an Unforeseen Cationic Iridium Complex
Abstract Ambiphilic molecules, which contain a Lewis base and Lewis acid, are of great interest based on their unique ability to activate small molecules. Phosphine boronates are one class of these substrates that have interesting catalytic activity. Direct access to these phosphine boronates is described through the iridium‐catalyzed C−H borylation of phosphines. An unconventional cationic iridium catalyst was identified as optimal for a range of phosphines, providing good yields and selectivity across a diverse class of phosphine boronates (isolated as the borane‐protected phosphine). A complimentary catalyst system (quinoline‐based silane ligand with [(COD)IrOMe]2) was optimal for biphenyl‐based phosphines. Selective polyborylation was also shown providing bis‐ and tris‐borylated phosphines. Deprotection of the phosphine boronate provided free ambiphilic phosphine boronates, which do not have detectable interactions between the phosphorus and boron atoms in solution or the solid state.
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- Award ID(s):
- 1764307
- PAR ID:
- 10084368
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 58
- Issue:
- 9
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 2834-2838
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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