N^Nvs.N^E (E = S or Se) coordination behavior of imino-phosphanamidinate chalcogenide ligands towards aluminum alkyls: efficient hydroboration catalysis of nitriles, alkynes, and alkenes

Abstract

The synthesis, characterization, and catalytic application of six aluminum alkyl complexes supported by various imino-phosphanamidinate chalcogenide ligands are described. Six different unsymmetrical imino-phosphanamidinate chalcogenide ligands [NHIRP(Ph)(E)NH-Dipp] [R = 2,6-diisopropylphenyl (Dipp),...

Tri-coordinated zinc alkyl complexes with N^S/Se coordination of imino-phosphanamidinate chalcogenide ligands as precursors for efficient hydroboration of nitriles and esters

“…3 and 4). 46 Additionally, in the 77 Se{ 1 H} NMR spectra of both 3b and 4b, a doublet was observed (at δ77 Se = −44.3 ppm and 1 J Se-P = 493.3 Hz for 3b; δ77 Se = 144.8 ppm and 1 J Se-P = 455.4 Hz for 4b) due to coupling between Se and P atom. For protic ligands 1b and 2b, the 77 Se{ 1 H} NMR signals also appeared as a doublet (at δ77 Se = −31.3 ppm and 1 J Se-P = 742.8 Hz for 1b; δ77 Se = −111.6 ppm and 1 J Se-P = 739.9 Hz for 2b) which were reported in our previous literature.…”

“…However, from the comparison of the coupling constant ( 1 J Se-P ) of the protic ligands (742.8 Hz for 1b and 739.9 Hz for 2b) with those of their corresponding zinc complexes (493.3 Hz for 3b and 455.4 Hz for 4b), it was observed that in metal complexes where metal-selenium bonds were present, the coupling constant value ( 1 J Se-P ) reduced substantially compared to those of the respective protic ligands (where metalselenium bonds were absent) which follow the same trend as that observed in other literature. 46,47 Suitable crystals of compounds 3a,b-4a,b were grown from a concentrated solution of toluene/hexane mixture (1 : 2) at room temperature for single-crystal X-ray diffraction analysis (Fig. 5-8).…”

Hydrosilylation of nitriles and tertiary amides using a zinc precursor

“…42 In the recent past, we have used numerous chemical approaches, such as hydroboration and silylation, under various reaction conditions in which alkenes, alkynes, nitriles, and carbonyls are employed to synthesize several organic compounds. [43][44][45][46][47] We are now interested in utilizing zinc bis (hexamethyldisilazide) as a single multitasking catalyst precursor in the hydrosilylation of nitriles and tertiary amides (Fig. 2).…”

Magnesium(ii) complexes supported by indole- and pyrrole-containing Schiff-base ligands: syntheses, structures, and applications as precatalysts in the hydroboration of nitriles and alkynes

“…Earth-abundant main group-metal complexes offer nontoxic, inexpensive and sustainable alternatives to precious transitionmetal catalysts in various synthetic transformations, especially in the hydroboration of carbon-heteroatom and carbon-carbon multiple bonds. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] These hydroboration reactions represent a series of atom-economic processes for the preparation of boroncontaining compounds. In these compounds, the boroncontaining groups could serve as functional handles for synthesizing new C-C bonds or for transforming boron-containing groups into halogen, alcohol, amine and amide functionalities.…”

“…In recent years, earth-abundant, nontoxic and inexpensive main group-metal compounds have become favourable catalysts in these research fields. [1][2][3][4][5][6][7] Several magnesium complexes, including Bu 2 Mg, b-diketiminate magnesium(I) complexes and ansa-half-sandwich magnesium complexes, 18,[61][62][63][64][65][66] can catalyze the hydroboration of nitriles or alkynes. However, compared with transition metal catalysts, magnesium complexes are very rare.…”