Schrock's metathesis catalyst electon deficient mo(vi), 14 electron species structural features pseudo-tetrahedral coordination sphere nar ligand, or ligands, and initial alkylidene need to be bulky to allow for isolation electron withdrawing alkoxides increase electrophilicity of metal center, hence increasing reactivity.
Olefin metathesis in organic synthesis wendy jen macmillan group meeting january 17, 2001 i well-defined alkene metathesis catalysts ii applications of olefin metathesis a ring closing metathesis b cross metathesis c ring opening metathesis recent reviews: furstner, a angew chem.
Ring-closing metathesis allows formation of cyclic alkenes ranging from 5 to 30 members, in which the e/z selectivity is related to the ring strain the 2 nd generation grubbs catalyst is more versatile for this reaction. It was not until the mid-1980s that well-defined, homogeneous catalyst systems were developed and investigated for a wide range of organic transformations, including: ring-closing metathesis (rcm), ring-opening metathesis polymerization (romp), acyclic diene metathesis polymerization (admet), ring-opening/cross metathesis (rocm), and cm (scheme 1. The olefin metathesis reaction (the subject of 2005 nobel prize in chemistry) can be thought of as a reaction in which all the carbon-carbon double bonds in an olefin (alkene) are cut and then rearranged in a statistical fashion.
• metathesis in acid-base chemistry and ion exchange is well defined and simple however, until recently, bond formation in organic reactants is difficult without the presence of catalysts • in the past 30 years or so industry has used olefin metathesis to form alkenes into other alkenes through a variety of mechanisms.
Ring closing metathesis (rcm) the ring-closing metathesis (rcm) allows synthesis of 5- up to 30-membered cyclic alkenes the e/z-selectivity depends on the ring strain the ru-catalysts used tolerate a variety of functional groups, but normally the molecule must have polar side chains that are able to build a template for the catalyst.