New synthesis and thermal studies of palladacycloalkanes and their precursors

Synthesis and reactivity of platinacycloalkanes

“…It can be seen that the chelating nature of diphosphine ligands gives much stability than the other ligands. The stability of metallacycloalkanes containing no substituents on the b-carbons follows the trend: Pt >> Pd > Ni [21].…”

“…with up to a 21-membered ring compound by this route (Scheme 1). This RCM method can also be extended to even number metallacycloalkane compounds [20] as well as other metals with a variety of ligand systems [21]. We also report the syntheses and spectroscopic characterization of interesting platinacycles through interand intra-molecular ring closing metathesis reactions and also describe the reactivity of these compounds.…”

Alkenyl complexes of platinum group metals: a platform for diverse reactivity patterns

“…We also prepared bis(1‐alkenyl)Pt(II) complexes ( 4 ) by reacting the appropriate Grignard reagents with Pt[COD]Cl 2 , followed by ligand displacement using various phosphine ligands (Scheme ) to obtain the corresponding L 2 Pt(1‐alkenyl) 2 complexes, where L = PPh 3 , t Bu 3 P; L 2 = dppe, dppp; n = 1–4 and 7 ( 5 , 6 , 7 , 8 , 9 , 10 ) . As this route is not limited to platinum, a similar route was employed for the synthesis of a series of bis(1‐alkenyl)Pd(II) complexes L 2 Pd[(CH 2 ) n CHCH 2 ] 2 with varying chain lengths (Scheme ) and also a series of bis(1‐alkenyl)Ir(III) complexes (equation ) …”

“…The small amount of n ‐decane could be the result of reductive elimination followed by hydrogenation. The source of hydrogen could be either the activation of solvent or the phenyl groups in phosphine ligands by the zerovalent metal species under those experimental conditions (equation ) …”

Thermolysis studies on platinacycloalkane complexes

“…Recently, we have discovered a novel route to medium and large, even and odd membered metallacycloalkanes from their metalealkenyl precursors, using a ring-closing metathesis reaction with Grubbs' catalysts (Scheme 1) [30e33]. In light of this, we have carried out thermolysis studies on a variety of metallacycloalkanes with Pt, Pd, Ir and Rh [34,35]. The purpose of this present article is to assess the stability of the different platinacycloalkanes with different ring sizes and to discuss the range of organic products produced upon their decomposition.…”