1,3,5-TRIMETHYL-1,3,5-TRIAZACYCLOHEXANE TRICARBONYL COMPLEXES OF MO AND W AS SOURCES OF THE FAC-M(CO)(3) FRAGMENT - MILD SYNTHESES OF FAC-[M(CO)(3)(CH3CN)(3)] (M = MO, W), [W(CO)(3)(PR3)(3)], [W(CO)(ALKYNE)(3)] AND [W(CO)(3)(PI-ARENE)] COMPLEXES

The 1,3,5-trimethyl-1,3,5-triazacyclohexane (Me(3)tach) group in [M(CO )(3)(Me(3)tach)] complexes (M=Mo, W) is easily displaced by a variety of ligands under mild conditions. The lability of the Me(3)tach ligand allows the [M(CO)(3)(Me(3)tach)] complexes to be used as synthetic in termediates in convenient syntheses of products such as fac-[M(CO)(3)( CH3CN)(3)] (M=Mo,W), [W(CO)(alkyne)(3)], [W(CO)(3)(PR3)(2)] and [W(CO) (3)(eta(6)-arene)] complexes. An improved synthesis of [W(CO)(3)(Me(3) tach)] from [W(CO)(6)] and Me(3)tach is described. (C) 1998 Elsevier S cience S.A. All rights reserved.