Experimental and theoretical investigation of the reactivity of [(BDI*)Ti(Cl){η²-P(SiMe₃)-PiPr₂}] towards selected ketones

Abstract

Reaction of [(BDI*)Ti(Cl){η2-P(SiMe3)-PiPr2}] with acetone led to new titanium complexes with a C–P–P bond by insertion of one molecule of acetone into two different Ti–P bonds (involving the phosphanyl phosphorus and the phosphido phosphorus atom).

Activation of the CP bond in phosphanylphosphaalkenes (CP–P bond system) in the reaction with nucleophilic reagents: MeLi, nBuLi and tBuLi

“…The 31 S4 and S5 †). The 31 P { 1 H}/ 1 H HMQC NMR spectrum shows that the phosphorus atom observed at 47.12 ppm correlates with protons at 1.21 ppm (tBu groups) and with protons at 2.91 ppm (weak correlation), while the phosphorus atom observed at À51.41 ppm indicates a strong correlation with protons at 2.91 ppm and a very weak correlation with protons observed at 1.03 ppm (see ESI, Fig.…”

“…The obtained results show that independently of the substituents in the phenyl ring and used lithium compounds, these reactions do not stop at the mono-substitution stage (compounds 3a-c and 4a-c were not observed in the reaction solutions) (Scheme 2). 31 P{ 1 H} NMR spectra of the reaction solution revealed that in each of these reactions appropriate triphosphane is formed: [tBu 2 P-P-{C(H)(3,5-tBu 2 C 6 H 3 )}-PtBu 2 ] À (2_3, 66.12 ppm, J PP ¼ 347.5 Hz, J PP ¼ 62.5 Hz; 57.98 ppm, J PP ¼ 231.7 Hz, J PP ¼ 62.5 Hz; À67.30 ppm, J PP ¼ 347.5 Hz, J PP ¼ 231.7 Hz) and [tBu 2 P-P-{C(H)(p-Me 2 N-C 6 H 4 )}-PtBu 2 ] À (2_4, 64.62 ppm, J PP ¼ 348.2 Hz, J PP ¼ 62.6 Hz; 56.85 ppm, J PP ¼ 239.6 Hz, J PP ¼ 62.6 Hz; À69.64 ppm, J PP ¼ 348.2 Hz, J PP ¼ 239.6 Hz). Additionally, the 31 P{ 1 H} NMR spectra show the compounds formation with a new C-C bond (3a 00 -3c 00 and 4a 00 -4c 00 ) and with three different phosphorus atoms, analogical to 1a 00 and 1b 00 compounds (see ESI Fig.…”

“…26 Changing the substituent on the phosphorus atom with a phosphanyl group leads to the formation of phosphanylphosphaalkene (C]P-P). [27][28][29][30][31][32] These diphosphorus analogs are a considerable and lesser known group of compounds, and their reactivity is practically unknown. Our main goal was to perform the rst step of anionic polymerization in solution (tetrahydrofuran, THF) at room temperature; for this purpose, we chose (biph)(H)C]P-PtBu 2 (1), (3,5-tBu 2 C 6 H 3 )(H)C]P-PtBu 2 (3) and (p-Me 2 N-C 6 H 4 )(H)C] P-PtBu 2 (4) containing an aldehyde derivative.…”

“…31 P{1 H} NMR (162 MHz, C 6 D 6 , 298 K) d: 66.05 (dd, J PP ¼ 347.5 Hz, J PP ¼ 62.5 Hz, [tBu 2 P-P-{C(H)(3,5-tBu 2 C 6 H 3 )}-PtBu 2 ] À ), 57.88 (dd, J PP ¼ 231.7 Hz, J PP ¼ 62.5 Hz, [tBu 2 P-P-{C(H)(3,5-tBu 2 C 6 H 3 )}-PtBu 2 ] À ), 54.07 (dd, J PP ¼ 325.2 Hz, J PP ¼ À ), À24.07 (dd, J PP ¼ 96.8 Hz, J PP ¼ 2.6 Hz, [P(nBu) 2…”

“…31 P{1 H} NMR (162 MHz, C 6 D 6 , 298 K) d: 64.73 (dd, J PP ¼ 348.2 Hz, J PP ¼ 62.6 Hz, [tBu 2 P-P-{C(H)(p-Me 2 N-C 6 H 4 )}-PtBu 2 ] À ), 57.05 (dd, J PP ¼ 237.7 Hz, J PP ¼ 62.6 Hz, [tBu 2 P-P-{C(H) (p-Me 2 N-C 6 H 4 )}-PtBu 2 ] À ), 54.84 (d, J PP ¼ 328.6 Hz, [P(nBu) 2 -CH(p-Me 2 N-C 6 H 4 )-CH(p-Me 2 N-C 6 H 4 )-P-(PtBu 2 )] À ), 39.77 (s, tBu 2 PLi), 19.81 (s, tBu 2 PH), À22.45 (d, J PP ¼ 109.6 Hz, [P(nBu) 2 -CH(p-Me 2 N-C 6 H 4 )-CH(p-Me 2 N-C 6 H 4 )-P-(PtBu 2 )] À ), À67.41 (dd, J PP ¼ 328.6 Hz, J PP ¼ 109.6 Hz, [P(nBu) 2 -CH(p-1…”