318498-29-2Relevant academic research and scientific papers
Hydrogen bonding and self-assembly in the crystal structures of ferrocenylmethanol derivatives having different phosphorus substituents on the ferrocene unit
Stepnicka, Petr,Cisarova, Ivana
, p. 1389 - 1396 (2007/10/03)
Ferrocenylmethanol derivatives bearing a phosphorus substituent in position two of the ferrocene unit, rac-2-(diphenylphosphino)ferrocenylmethanol (3), rac-2-(diphenylphosphinoyl)ferrocenylmethanol (4), and rac-2-(diphenylthiophosphoryl)ferrocenylmethanol (5), have been synthesized and structurally characterized by single-crystal X-ray diffraction. While the overall molecular geometry does not differ significantly in the whole series, showing only differences in the arrangement at the phosphorus atom owing to a replacement of the lone electron pair (2, 3) with oxygen (4) and sulfur (5), and in the conformation of the hydroxylmethyl group, the compounds form different crystal packing patterns that result from a counterplay of hydrogen bonding of various types and non-polar interactions. Alcohol 3 associates into dimers by double O-H···O hydrogen bridges between disordered hydroxy groups of neighbouring molecules. The distribution of molecules in the crystal of 4 appears identical to that of 3. However, the structure of 4 comprises intermolecular O-H···O=P hydrogen bridges instead. The packing of phosphine sulfide 5 is different, featuring intramolecular O-H···S bridges. Although the molecular entities are involved in further interactions such as O-H···P and C-H···O hydrogen bonding, and π-π stacking interaction of the phenyl rings, which further propagate the molecular network, the principal force towards self-assembly always results in the formation of entropically favoured, closed cyclic systems. The solid state structure of the common precursor, rac-2-(diphenylphosphino)ferrocenylmethyl acetate (2) shows only C-H···O intermolecular interactions due to the lack of a better hydrogen bond donor.
A Novel Approach to Ferrocenes with Planar Chirality
Ganter, Christian,Wagner, Trixie
, p. 1157 - 1162 (2007/10/03)
The 2-metalation of enantiomerically pure (S)-(2-methoxymethylpyrrolidin-1-yl)ferrocene FcSMP (1) with BuLi proceeds with high diastereoselectivity (up to 98percent de) to yield the Ph2P-substituted ferrocene (S,Sp)-2a after quenching with Ph2PCl.The SMP moiety was removed by heating of 2a at reflux in acetic anhydride to give planar chiral (Sp)-2-diphenylphosphanylferrocenylmethyl acetate (5).The diastereoisomer (S,Rp)-2b was synthesized from 1 by intermediately blocking the primary metalation site with a Me3Si group which can be removed afterwards by treatment with KO(t-Bu) in DMSO.Compound 2a was treated with 2 to give the complex PF6 (7*PF6).The structure of 7*PF6 was determined by a single-crystal X-ray diffraction study and showed 2a to act as a bidentate P,N-chelate ligand. - Keywords: Ferrocenes, planar chiral; Deprotonation, diastereoselective; Palladium complexes; Chelating P,N-ligands
