Interaction of Acyclic Tetraenes and Trienes with Transition Metals: Organoiron Compounds
作者:P. W. Jolly、C. Kopiske、C. Krueger、A. Limberg
DOI:10.1021/om00004a048
日期:1995.4
The tetraene 3,6-dimethylene-1,7-octadiene (DMOD) reacts with zerovalent [FePR(3)] species (prepared by reduction of FeCl2 . nTHF with active Mg in the presence of the donor ligand) to give (eta(4),eta(4) -DMOD)FePR(3) compounds. The crystal structure of the PPh(3)-stabilized derivative (space group R ($) over bar 3, a = b = c = 20.290(9) Angstrom, alpha = beta = gamma = 117.47(3)degrees, Z = 6, R = 0.048, R(W) = 0.052) confirms that the iron atom lies at the center of a square pyramid with the P atom at the apex and the two 1,3-diene fragments forming the base. That the products of the reaction of the trienes 3-methylene-1,6-heptadiene (MHD) and 3-methylene-1,7-octadiene (MOD) with zerovalent [Fe((Pr2P)-P-i(CH2)(n)PPr2i)] species (n = 1, 2, 3) contain a triene molecule bonded in an eta(2),eta(4)-manner to the metal atom has been confirmed by X-ray diffraction for (eta(2),eta(4)-MHD)Fe((Pr2PC2H4PPr2i)-P-i) (space group P2(1)/c, a = 11.831(1) Angstrom, b = 9.744(1) Angstrom, c = 20.917(2) Angstrom, beta = 104.87(1)degrees, Z = 4, R 0.042, R(W) = 0.039). Warming a red ethereal solution of (eta(2),eta(4)-MOD)Fe((Pr2PC3H6PPr2i)-P-i) to room temperature causes dissociation of the nonconjugated double bond of the triene to give the green, paramagnetic compound (eta(4)-MOD)Fe(Pr-2(i)-PC3H6PPr2i) which reacts with CO to give the yellow, diamagnetic compound (eta(4)-MOD)Fe(CO)((Pr2PC3H6PPr2i)-P-i).