Configurationally stable metal-centered chirality: stereospecific and regioselective rhodaacylation of alkynes controlled by the third generation of the [Cp′-P]H ligand

Abstract

The rhodium cationic complex [[h5 +h 1 -{3-(NIM)Ind-P} n = 2 ]Rh(CO)Me]BF 4 (1) reacts with 1-phenylpropyne regioselectively and stereospecifically to afford the alkenyl complex [[h 5 +h 1 -{3-(NIM)Ind-P} n = 2 ]Rh{h 2 -ONC(CH 3 )-C(CH 3 )NCPh}]BF 4 (2).

Alkyne oligomerization mediated by rhodium complexes with a phosphinosulfonamido ligand and isolation and characterization of a rhodacyclopentadiene complex

“…The structural features of the five-membered metallacyle are similar to other structurally characterized rhodacyclopentadienes. The bond distances associated with the Rh(g 2 -C(C"CCO 2 Et)@CHCO 2 Et) are comparable to those reported for the related complexes [(g 5 :g 1 -(3-NIM)Ind-P)Rh(g 2 -CPh@CMeCMe@O)] ((3-NIM)Ind-P, a phosphorus-containing indenyl ligand) [16] and [Cp*RhCl-(l-SPr)(l-S(i-Pr)C@CHCO 2 Me)RhCp*]OTf [17]. The solid-state structure is supported by the NMR spectroscopic data.…”

New Reactions of Cyclopentadienylnickel Chelates with Secondary Phosphane Tethers

“…The 1 H NMR spectra show the signals of the cyclopentadienyl protons at lower field than in the case of the bromo complex 8, presumably as a result of the cationic nature of the complexes. This is also reflected by the 13 Hz. 32, which contains two stereogenic phosphorus atoms and might therefore exist as a meso and as a rac diastereomer, shows only one signal set in the 13 C and 31 P NMR spectra.…”

“…[17] 21 was characterized spectroscopically. Key features are the CN absorption band in the IR spectrum atñ = 2160 cm À 1 , the observation of the molecular ion in the mass spectrum (m/z = 454) and the expected signals in the 1 H and 13 C NMR spectra, which reflect the asymmetry of the compound. The signal assigned to the proton bound at phosphorus is observed at δ = 6.12 ppm as a ddd signal with a P,H coupling constant of 1 J P,H = 353.9 Hz.…”

“…[2] In some cases, however, the cyclopentadienyl as well as the phosphane moieties have been the subject of variations, for example by replacement of the cyclopentadienyl by an indenyl or fluorenyl system. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] Variations at the phosphane part include unsymmetrical substitution patterns such as phenyl/alkyl, [5] alkyl/ silyl, [17] or rare cases of secondary phosphane moieties. [17,18] We have investigated complexes such as 2-5 with cobalt, nickel and iron as the metal centers for a long time (Scheme 2).…”

New cyclopentadienylethylphosphane chelate complexes with unsymmetrical phosphane substitution

“…These reactions proceeded with high diastereoselectivity. [54][55][56]72,73 The Salzer group prepared a [(diphenylphosphanyl)ethylcyclopentadienyl]-ethenerhodium(I) chelate with a methyl substituent at the carbon atom next to phosphorus in enantiomerically pure form. In addition, the corresponding indenyl and fluorenyl complexes were reported.…”