Olefin Metathesis by Well-Characterized Re(VII) Alkylidene/Alkylidyne Complexes

Abstract

ABSTRACT. A convenient one pot synthesis of Re(NR)z(py)Cl3 from Re207, trimethyl-chlorosilane, pyridine, and RNH2 (R = aryl or t-butyl) has been developed.

Reactions of Tungsten Alkylidynes with Thionyl Chloride

“…The bond lengths within the metallacycle are consistent with its description as a dithiocarboxylatocarbene chelated by a dative S(1)→W interaction [2.520(2) Å]. To the best of our knowledge no previous example of such a metallacycle has been structurally characterized, and high-valent metal complexes of alkylidene ligands bearing π-dative substituents remain rare . The W−C(4) separation at 2.043(6) Å clearly reflects multiple bonding, but is significantly longer than for the alkylidene ligand in Schrock's benchmark complex [W(⋮CBu t )(CHBu t )(CH 2 Bu t )(dmpe)] [WC 1.942(9) Å]. , The presence of π-dative carbene substituents is generally held to compromise metal−carbon dπ−pπ overlap, and this might be expected to be encouraged by electrophilic metal centers.…”

High Oxidation State Multiple Metal−Carbon Bonds

“…Compounds of the type Re(CCMe 2 R)(CHCMe 2 R)[OC(CF 3 ) 2 Me] 2 react readily with olefins. , 1-Decene and methyl-9-decenoate react with Re(C−t-Bu)(CH−t-Bu)(OR F6 ) 2 to give Re(C−t-Bu)[CH(CH 2 ) 7 Me](OR F6 ) 2 and Re(C−t-Bu)[CH(CH 2 ) 7 CO 2 Me](OR F6 ) 2 , respectively (OR F6 = OCMe(CF 3 ) 2 ). The new alkylidene complexes are unstable in the presence of excess terminal olefin and decompose upon attempted isolation.…”

Synthesis of Rhenium(V) 2,4,6-Trimethylbenzylidyne Complexes by Abstracting "O2-" from an Acyl with Triflic Anhydride

“…Re(C-2,4,6-C6H3Me3)(CO)jCl2(py) (4). Pyridine (1.71 mL, 2.11 mmol) and T1BF4 (615 mg, 2.11 mmol) were added to the mixture containing 3 and Et4NOTf described above.…”