TY - JOUR

T1 - Platinum Complexes with Chelating Acyclic Aminocarbene Ligands Work as Catalysts for Hydrosilylation of Alkynes

AU - Chay, Rogério S.

AU - Rocha, Bruno G.M.

AU - Pombeiro, Armando J.L.

AU - Kukushkin, Vadim Yu

AU - Luzyanin, Konstantin V.

PY - 2017/10/31

Y1 - 2017/10/31

N2 - This work describes the preparation of a series of platinum-aminocarbene complexes [PtCl{C(N=C a (C 6 R 2 R 3 R 4 R 5 CON b ))=N(H)R 1 }(CNR 1 )] a-b (8-19, 65-75% isolated yield) via the reaction of cis-[PtCl 2 (CNR 1 ) 2 ] (R 1 = Cy 1, t-Bu 2, Xyl 3, 2-Cl-6-MeC 6 H 3 4) with 3-iminoisoindolin-1-ones HN=C a (C 6 R 2 R 3 R 4 R 5 CON b H) (R 2 -R 5 = H 5; R 3 = Me, R 2 , R 4 , R 5 = H 6; R 3 , R 4 = Cl, R 2 , R 5 = H 7). New complexes 17-19 were characterized by elemental analyses (C, H, N), ESI + -MS, Fourier transform infrared spectroscopy (FT-IR), one-dimensional ( 1 H, 13 C{ 1 H}), and two-dimensional ( 1 H, 1 H correlation spectroscopy (COSY), 1 H, 13 C heteronuclear multiple quantum correlation (HMQC)/ 1 H, 13 C heteronuclear single quantum coherence (HSQC), 1 H, 13 C heteronuclear multiple bond correlation (HMBC)) NMR spectroscopy, and authenticity of known species 8-16 was confirmed by FT-IR and 1 H and 13 C{ 1 H} NMR. Complexes 8-19 were assessed as catalysts for hydrosilylation of terminal alkynes with hydrosilanes to give vinyl silanes, and complex [PtCl{C(N=C a (C 6 H 3 (5-Me)CON b ))=N(H)(2-Cl-6-MeC 6 H 3 )}{CN(2-Cl-6-MeC 6 H 3 )}] a-b (18) showed the highest catalytic activity. The catalytic system proposed operates at 80-100 °C for 4-6 h in toluene and with catalyst loading of 0.1 mol %, enabling the reaction of a number of terminal alkynes (PhC≡CH, t-BuC≡CH, and 4-(t-Bu)C 6 H 4 C≡CH) with hydrosilanes (Et 3 SiH, Pr 3 SiH, i-Pr 3 SiH, and PhMe 2 SiH). Target vinyl silanes were prepared in 48-95% yields (as a mixture of α/β isomers) and with maximum turnover number of 8.4 × 10 3 . Hydrosilylation of internal alkynes (PhC≡CPh, Me(CH 2 ) 2 C≡C(CH 2 ) 2 Me, and PhC≡CMe) with hydrosilanes (Et 3 SiH, PhMe 2 SiH) led to the corresponding trisubstituted silylated alkenes in 86-94% yields. Initial observations on the mechanism of the catalytic action of platinum-ADC catalysts 8-19 suggested a molecular catalytic cycle.

AB - This work describes the preparation of a series of platinum-aminocarbene complexes [PtCl{C(N=C a (C 6 R 2 R 3 R 4 R 5 CON b ))=N(H)R 1 }(CNR 1 )] a-b (8-19, 65-75% isolated yield) via the reaction of cis-[PtCl 2 (CNR 1 ) 2 ] (R 1 = Cy 1, t-Bu 2, Xyl 3, 2-Cl-6-MeC 6 H 3 4) with 3-iminoisoindolin-1-ones HN=C a (C 6 R 2 R 3 R 4 R 5 CON b H) (R 2 -R 5 = H 5; R 3 = Me, R 2 , R 4 , R 5 = H 6; R 3 , R 4 = Cl, R 2 , R 5 = H 7). New complexes 17-19 were characterized by elemental analyses (C, H, N), ESI + -MS, Fourier transform infrared spectroscopy (FT-IR), one-dimensional ( 1 H, 13 C{ 1 H}), and two-dimensional ( 1 H, 1 H correlation spectroscopy (COSY), 1 H, 13 C heteronuclear multiple quantum correlation (HMQC)/ 1 H, 13 C heteronuclear single quantum coherence (HSQC), 1 H, 13 C heteronuclear multiple bond correlation (HMBC)) NMR spectroscopy, and authenticity of known species 8-16 was confirmed by FT-IR and 1 H and 13 C{ 1 H} NMR. Complexes 8-19 were assessed as catalysts for hydrosilylation of terminal alkynes with hydrosilanes to give vinyl silanes, and complex [PtCl{C(N=C a (C 6 H 3 (5-Me)CON b ))=N(H)(2-Cl-6-MeC 6 H 3 )}{CN(2-Cl-6-MeC 6 H 3 )}] a-b (18) showed the highest catalytic activity. The catalytic system proposed operates at 80-100 °C for 4-6 h in toluene and with catalyst loading of 0.1 mol %, enabling the reaction of a number of terminal alkynes (PhC≡CH, t-BuC≡CH, and 4-(t-Bu)C 6 H 4 C≡CH) with hydrosilanes (Et 3 SiH, Pr 3 SiH, i-Pr 3 SiH, and PhMe 2 SiH). Target vinyl silanes were prepared in 48-95% yields (as a mixture of α/β isomers) and with maximum turnover number of 8.4 × 10 3 . Hydrosilylation of internal alkynes (PhC≡CPh, Me(CH 2 ) 2 C≡C(CH 2 ) 2 Me, and PhC≡CMe) with hydrosilanes (Et 3 SiH, PhMe 2 SiH) led to the corresponding trisubstituted silylated alkenes in 86-94% yields. Initial observations on the mechanism of the catalytic action of platinum-ADC catalysts 8-19 suggested a molecular catalytic cycle.

UR - http://www.scopus.com/inward/record.url?scp=85041125672&partnerID=8YFLogxK

U2 - 10.1021/acsomega.7b01688

DO - 10.1021/acsomega.7b01688

M3 - Article

AN - SCOPUS:85041125672

VL - 3

SP - 863

EP - 871

JO - ACS Omega

JF - ACS Omega

SN - 2470-1343

IS - 1

ER -