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Ring-closing metathesis (RCM) is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the intramolecular metathesis of two terminal alkenes, which forms the cycloalkene as the E-or Z-isomers and volatile ethylene.
In one study published by Grubbs and Hong in 2006, a water-soluble Grubbs catalyst was prepared by attaching a polyethylene glycol chain to the imidazolidine group. [20] This catalyst is used in the ring-closing metathesis reaction in water of a diene carrying an ammonium salt group making it water-soluble as well.
Grubbs was instrumental in developing a family of ruthenium catalysts, including Grubbs catalyst for olefin metathesis. [36] He studied olefin transformations for ring-closing metathesis (RCM), [37] cross-metathesis reaction (CMR), [38] and ring-opening metathesis polymerization (ROMP) with cyclic olefins such as norbornene. [39]
The reverse reaction of RCM, ring-opening metathesis, can likewise be favored by a large excess of an alpha-olefin, often styrene. Ring-opening metathesis usually involves a strained alkene (often a norbornene) and the release of ring strain drives the reaction. Ring-closing metathesis, conversely, usually involves the formation of a five- or ...
An enyne metathesis is an organic reaction taking place between an alkyne and an alkene with a metal carbene catalyst forming a butadiene. This reaction is a variation of olefin metathesis. [1] The general scheme is given by scheme 1: When the reaction is intramolecular (in an enyne) it is called ring-closing enyne metathesis or RCEYM (scheme 2):
Staples synthesized using ring-closing metathesis (RCM) are common. [8] This variation of olefin metathesis and its application to stapled peptides was developed by Nobel laureate Robert H. Grubbs and Helen Blackwell in the late 1990s, who used the Grubbs catalyst to cross-link O-allylserine residues in a covalent bond. [10]
Frontal ring-opening metathesis polymerization (FROMP) is a variation of ROMP. It is a polymerization system that only reacts on a localized zone. [10] One example of this system is the FROMP of dicyclopentadiene with a Grubbs' catalyst initiated by heat. [11]
Tris(hydroxymethyl)phosphine can also be used to synthesize the heterocycle, N-Boc-3-pyrroline by ring-closing metathesis using Grubbs' catalyst (bis(tricyclohexylphosphine)benzylidineruthenium dichloride). N-Boc-diallylamine is treated with Grubbs' catalyst