×. Ch-ard, J. Pc-=-3-hz, . Ch-ars, C. Ch-ar-hz, C. Ar et al., 0 (s, 2 × CH Ar, .9 Hz, 2 × CH Ar ), 140.5 (d, J PC = 0.9 Hz, C Ar )): ? ?50.8 (d, J SiRh = 104.5 Hz, SiRh), 11.7 (d, J SiP = 1.9 Hz, SiMe). 31 P{ 1 H} NMR (121.49 MHz, THF-d 8 , 25 °C): ? 48.6 (s). Minor isomer (8%). 31 P{ 1 H} NMR (121.49 MHz, THF-d 8 , 25 °C): ? 43, p.80

I. Silacyclopropylidene-rh and . Cl, In a pressurized NMR tube, a solution of 2 (40.0 mg, 0.042 mmol) in CDCl 3 was exposed to a CO atmosphere (5 bar) After 5 min of stirring, the bright-yellow solution of 3 was analyzed by NMR. A solution of 2 (120.0 mg, 0.126 mmol), CH 2 Cl 2 (2 mL) was put under stirring at RT. After 10 min of CO bubbling in the solution, the resulting yellow solid of 3 was used to prepare KBr pellets suitable for IR analysis

1. Hz, J. Ch-iprd, 1. Ph-=-30-hz, 1. Sich, T. Ncch-bridgehead et al., 13 C{ 1 H} NMR (75.47 MHz, THF-d 8 , 25 °C): ? 2.5 (d, J PC = 2.1 Hz, CH 3 Si), 5.3 (d, J PC = 1.1 Hz, CH 3 Si), 24.0 (s, CH 3iPr (s, CH 3iPr (s, CH 3iPr ), 27.8 (s, CH 2 C bridgeheadCN ), 28.0 (s, CH iPr, 25.5 (br, CH 2 C bridgeheadCP ), 25.6 (s, CH 3iPr ), pp.41-44

. Hz, . Pc?cn-)-s, . Ch-ars, . Ch-ars, C. Ch-ars et al., 1 (s, 2 × CH Ar, pp.132-137

C. Hz, J. Ard, ×. Pc-=-6, and . Ch-ar, (br s, 2 × C Ar ), 175.5 (d, J PC = 10 (s, SiMe). 31 P{ 1 H} NMR (121.49 MHz, THF-d 8 , 25 °C): ? 46.6 (s). IR (KBr pellets): ? CO, pp.139-148, 1984.

I. Silacyclopropylidene-cu and . Complex, To a flask containing 1 (40.0 mg, 0.057 mmol) and CuCl (5.6 mg, 0.057 mmol) was added THF (1 mL) at RT. After stirring overnight at RT, all volatiles were removed under vacuum, and the solid was washed with pentane, p.98

J. Hh, CDCl 3 , 25 °C): ? 0.04 (s, 3H, CH 3 Si, ?30 °C. Mp: 158?159 °C. Major isomer (92%). 1 H NMR (300.18 MHz, pp.0-491625

1. Hz and J. Hh, 1.34 (m, 1H, 1 / 2 CH 2 C bridgeheadCP ), 1.49 (s, 9H, 3 × CH 3tBu ), 1.60 (d, J HH = 6, 2H, CH 2 C bridgeheadCN ), 2.47 (s, 1H, PCCH bridgehead ), p.6197

1. Hz, 1. Sichs, 3. Ar, 2. Arbr, and . Ar, 13 C{ 1 H} NMR (75.47 MHz, CDCl 3 , 25 °C): ? 3 (s, CH 3iPr ), 26.7 (s, CH 3iPr, 24.6 (s, CH 3iPr ), 24.6 (s, CH 2 C bridgeheadCP ), pp.2738-2744

C. Hz, ×. Ar, and . Ch-ar, 0 (s, C Ar ), 148.1 (s, C Ar ) (s), pp.25-41

I. Silacyclopropylidene-au, 1. Complex, 2. , and H. Ar, 034 mmol) was added THF (0.5 mL) at RT. After 15 min of stirring at RT, THF was removed, and the solid was washed with pentane, to give the analytically pure 5 as a light-violet powder (29.7 mg, 92%) Crystals of compound 5 suitable for X-ray diffraction analysis were obtained by slow crystallization in chloroform at RT, 034 mmol) and AuCl(SMe 2 ) (10.1 mg Mp: 240?241 °C. Major isomer (92%). 1 H NMR (300.18 MHz, CDCl 3 , 25 °C): ? 0.08 (s, 3H, CH 3 Si), 0.59 (s, 3H, CH 3 Si) 1.49 (m, 1H, 1 / 2 CH 2 C bridgeheadCP ), 1.58 (s, 9H, 3 × CH 3tBu ), 1.68 (br d, J HH = 8.50 Hz 1H, SiCH), 3.39 (s, 1H, NCCH bridgehead ), pp.2-63

C. Iprd, J. Pc-=-3d, J. Pc-=, . Ch-ars, C. Ch-ars et al., 5 (s, CH 3iPr7 (s, CH 2 C bridgeheadCP ), 25.0 (s, CH 3iPr ), 26.0 (s, CH 3iPr3 (s, CH 3iPr7 (s, CH 2 C bridgeheadCN ), H} NMR (75.47 MHz, CDCl 3 , 25 °C): ? 3.5 (d, J PC = 2.1 Hz, CH 3 Si), 6.2 (d, J PC = 0.9 Hz Hz, SiCH), 28.9 (s, CH iPr ), 32.4 (d, J PC = 5.0 Hz, 3C, 3 × CH 3tBu ) °C): ? ?28.8 (d, J PSi = 1.4 Hz, SiAu), pp.138-138

H. Nmr, 49 MHz, CDCl 3 , 25 °C): ? 45.5 (s) Minor isomer (8%)

C. Sis, . Ars, . Ch-ars, . Ch-ars, . Ch-ars et al., 6 (s, CH 3iPr, 32.7 (d, J PC = 5.2 Hz, 3C, 3 × CH 3tBu ), 33.2 (d, J PC = 4.5 Hz, 3C, 3 × CH 3tBu ), 36.0 (t, J PtC = 51.0 Hz, 2C, 2 × H 2 CCH), 41.0 (s, H 2 CCH), 41.4 (s, H 2 CCH) 129.8 (s, 2 × CH Ar ), 134.0 (d, J PC = 4.5 Hz, C Ar ), 136.7 (d, J PC = 7.5 Hz, 2 × CH Ar, pp.27-34

. Hz, 195 Pt{ 1 H} NMR (107.55 MHz, CDCl 3 , 25 °C): ? 5969 (s)

?. References-crudden, C. M. Allen, D. P. Hahn, F. E. Jahnke, M. C. De-fre?montfre?mont et al., (e) N-heterocyclic carbenes in transition metal catalysis Topics in Organometallic Chemistry, Coord. Chem. Rev. Angew. Chem., Int. Ed. Coord. Chem. Rev. Angew. Chem., Int. Ed, vol.47, issue.41, pp.3122-862, 2002.

M. Wagner and N. Metzler, (b) For a recent review on transition-metal NHSi complexes, see: Blom, J. Am. Chem. Soc. B, vol.116, p.2691, 1994.

M. O. Driess, B. Blom, S. Enthaler, S. Inoue, E. Irran et al., Hydrosilylation of ketones catalyzed by a monodentate donorstabilized silylene-Fe 0 complex, J. Am. Chem. Soc, vol.33, issue.13510, pp.6885-6703, 2014.

J. Liedtke and H. Ru?-egger, Phosphiranes as Ligands for Platinum Catalysed Hydrosilylations, Tetrahedron, vol.56, issue.1, p.143, 2000.
DOI : 10.1016/S0040-4020(99)00783-8

J. Sotiropoulos, A. Baceiredo, and R. Rodriguez, Inorganic Chemistry Article DOI: 10.1021/acs.inorgchem, Angew. Chem., Int. Ed. Inorg. Chem. N, vol.51, issue.5517, pp.7158-8234, 2012.

T. Kato, . Angew, . Chem, . E. Int, G. Kuchenbeiser et al., No detectable degradation of 2 was observed after its toluene solution was heated at 110 °C for several hours. (19) See the Supporting Information, J. Organomet. Chem. Angew. Chem., Int. Ed, vol.521820, issue.4422, pp.8980-899, 2005.

D. Gallego, E. Irran, and M. Driess, (24) A four-coordinate Cu I -I complex with the NHSi ligand is known, Chem. -Eur. J. Avent, A. G.; Gehrhus, B P. B, vol.20, p.9400, 2014.

H. J. Maciejewski, . Organomet, G. Chem-tan, B. Blom, D. Gallego et al., CCDC 1456921 (5), and CCDC 1456922 (6) contain the supplementary crystallographic data for this paper These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccddc.cam. ac.uk/data_request/cif, CCDC Angew. Chem., Int. Ed. Engl. Organometallics Khan, S.; Pal, S.; Kathewad, N.; Purushothaman, I. P. Chem. Commun. J, vol.686, issue.540128, pp.321-346, 1990.

M. Hoffmann, A. Ziarko, K. Szubert, M. Majchrzak, S. Rubinsztajn et al., (35) The issue concerning the deactivation of a platinum catalyst due to the formation of platinum colloidal species is actually controversial, Appl. Catal., A, vol.362, pp.106-140, 2009.