A multidentate and flexible diolefin-diphosphine ligand, based on the dibenzylidene acetone core, namely dbaphos (1), is reported herein. The ligand adopts an array of different geometries at Pt, Pd and Rh. At Pt(II) the dbaphos ligand forms cis- and trans-diphosphine complexes and can be defined as a wide-angle spanning ligand. (1)H NMR spectroscopic analysis shows that the β-hydrogen of one o...

Methyltrioxorhenium (MTO) complexed with pyridine was shown to be a highly effective catalyst for the regioselective monoepoxidation of conjugated di- and trienes using 30% H2O2 at or below room temperature. The resultant allylic epoxides, and the triols derived from them, are versatile synthetic intermediates as well as substructures present in many bioactive natural products. The site of epox...

A series of CoIII carboxylate based upon N,N,O,O-tetradentate Schiff base ligand framework have been prepared. X-ray diffraction analysis confirms that these Schiff base CoIII carboxylate are all monomeric species with a six-coordinated central Co in their solid structures. The activities and polycarbonate selectivity of these complexes toward the copolymerization of epoxide (cyclohexene oxide ...

DSC analysis is conducted to obtain kinetic information of the chain addition copolymerization in bulk of a quad-monomer acrylic system. The experimental variables include reaction temperature, type of peroxide and peroxide concentration. By assuming that the copolymerization is a simple reaction, the approximate apparent order of the reaction can be identified; and along with the heat of react...

The cycloisomerization of 1,5-enynes catalyzed by cationic triphenylphosphinegold(I) complexes produces bicyclo[3.1.0]hexenes. Substitution at all positions of the 1,5-enyne is tolerated, leading to a wide range of bicyclo[3.1.0]hexane structures, including those containing quaternary carbons. Substrates containing a 1,2-disubstituted olefin undergo stereospecific cycloisomerization (cis-olefin...

Five years have passed since the first publication of the Thematic Series on Olefin Metathesis in the Beilstein Journal of Organic Chemistry [1]. During these years the research continued to progress at full speed. Astute readers of this Thematic Series, as well as readers of the recent books devoted to olefin metathesis [2,3], can easily see that a great number of studies in this field have ad...

Aliphatic polyesters constitute an important class of polymers because of their biodegradability1,2 and biocompatability,2,3 which enable their use in drug delivery systems,2 artificial tissues,3 and commodity materials.4 Polyesters such as poly(butylene succinate) are commonly produced through condensation polymerization; however, this method is energy intensive, requiring high temperature and...

We describe the synthesis of a series of interlocked structures from porphyrin-glycoluril cage compounds and bis(olefin)-terminated viologens by an olefin-metathesis protocol. The length of the chain connecting the olefin substituents with the viologen has a marked effect on the products of the ring-closure reaction. Long chains give [2]- and [3]catenane structures, whereas short chains give a ...

The title compound, [Co(C10H15)(C2H4)2], was prepared by Na/Hg reduction of [Co2(C10H15)2(μ-Cl)2] in THF under an ethyl-ene atmosphere and crystallized from pentane at 193 K. The Co-C(olefin) bonds have an average length of 2.022 (2) Å, while the Co-C(penta-dien-yl) bonds average 2.103 (19) Å. The olefin C=C bonds are 1.410 (1) Å. The dihedral angle between the planes defined by the cyclo-penta...