Solvent-Mediated Functionalization of Benzofuroxan on Electron-Rich Ruthenium Complex Platform

An unprecedented reactivity profile of biochemically relevant R-benzofuroxan (R=H, Me, Cl), with high structural diversity and molecular complexity on a selective {Ru(acac)(2)} (acac=acetylacetonate) platform, in conjugation with EtOH solvent mediation, is revealed. This led to the development of monomeric [Ru-III(acac)(2)(L-1R)] (1a-1c; L-1R=2-nitrosoanilido derivatives) and dimeric [{Ru-II(acac)(2)}(2)(L-2R)] (2a-2b; L-2R=(1E,2E)-N-1,N-2-bis(2-nitrosophenyl)ethane-1,2-diimine derivatives) complexes in one pot with a change in the metal redox conditions. The functionalization of benzofuroxan in 1 and 2 implied in situ reduction of N=O to NH- in the former and solvent-assisted multiple N-C coupling in the latter. The aforesaid transformation processes were authenticated through structural elucidation of representative complexes, and evaluated by their spectroscopic/electrochemical features, along with C2D5OD labeling and monitoring of the impact of substituents (R) in the benzofuroxan framework on the product distribution process. The noninnocent potential of newly developed L-1 and L-2 in 1 and 2, respectively, was also probed by spectroelectrochemistry in combination with DFT calculations.