Multicomponent reactions of urea and its derivatives with CH2O and H2S in the synthesis of 1,3,5-thiadiazinane thi ones and macroheterocycles. Improved synthesis of 2-arylhydrazonohydroxypropanones and their utility in efficient synthesis of pyridazine derivatives. PDF ali, koany abdallah khalil Synthesis and reactions of 2,6-bis[3-oxopropanenitrile N,N-dimethylamino methylene]pyridine.
What is claimed is: A compound of formula I-c: The compound of claim 1, wherein: The compound of claim 3, wherein the compound promotes Z-selective olefin metathesis reactions.
A compound of formula IX: The compound of claim 1, wherein R is —OR, wherein R is optionally substituted phenyl.
The compound of claim 3, wherein R4 is —N R 2, wherein the two R groups are taken together with the nitrogen to form an optionally substituted membered saturated, partially unsaturated, or aryl ring having additional heteroatoms not including the N atom from —N R 2 independently selected from nitrogen, oxygen, or sulfur.
The compound of claim 8, wherein R4 is The compound of claim 3, wherein the compound is selected from: The compound of claim 1, wherein n is 0. The compound of claim 1, wherein R1 is optionally substituted C aliphatic, and R2 is hydrogen.
A compound or compound complex comprising the compound of claim 1 and a Lewis acid. The compound or compound complex of claim 16, wherein the Lewis acid comprises a boron atom. The compound or compound complex of claim 17, wherein the Lewis acid is B C6F5 3. The compound of claim 20, wherein: R3 is an optionally substituted group selected from: R4 is —N R 2, wherein the two R groups are taken together with the nitrogen to form an optionally substituted membered saturated, partially unsaturated, or aryl ring having additional heteroatoms not including the N atom from —N R 2 independently selected from nitrogen, oxygen, or sulfur.
The compound of claim 21, wherein R4 is optionally substituted pyrrolyl. The compound of claim 20, wherein each of R3 and R4 is independently substituted The compound of claim 25, wherein R3 and R4 are different.
A great number of commercially important molecules contain olefins. Such specialty chemicals include biologically active molecules, oleochemicals, renewables, fine chemicals, and polymeric materials, to name a few.
Moreover, many reactions in organic chemistry require alkenes as starting materials. Accordingly, there remains an unmet need for improved methods and catalysts for metathesis reaction.
Thermal ellipsoid drawing of I Hydrogen atoms have been omitted for clarity. Solvent molecules are not shown. Typical 1H NMR spectrum of the product of 1-octene homocoupling mixture.
The asterisk denotes residual ethylene. Hydrogen atoms, except for those on the metallacycle, have been omitted for clarity. Only the major component of disorder is shown. Hydrogen atoms, except for those on the methylidene, have been omitted for clarity.
General Description of Certain Embodiments of the Invention Early in the development of olefin metathesis catalysts that contain tungsten, it was shown that metathetically more active and reproducible systems were produced when tungsten oxo complexes were deliberately employed or were present as impurities in WCl6 K.
San Diego, ; K. The possibility that oxo alkylidene complexes, e. Organometallics1, Compound 1 was the first high oxidation state tungsten alkylidene complex that would both i metathesize terminal and internal olefins in the presence of a trace of AlCl3 and ii produce a new alkylidene that could be observed as a consequence of olefin metathesis.
The three most likely possibilities for the role of AlCl3 are removal of halide to give monocationic or dicationic species, removal of a phosphine to give the 16 electron monophosphine adduct Wengrovius, J. By the time 1 was discovered, tantalum alkylidene complexes had been turned into functional olefin metathesis catalysts through use of alkoxides as ligands Rocklage, S.
Polyhedron14, Hexacoordinate Ru-based olefin metathesis catalysts with pH-responsive N-heterocyclic carbene (NHC) and N-donor ligands for ROMP reactions in non-aqueous, aqueous and emulsion conditions.
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Synfacts Issue 10 · Z-Selective Ring Opening/Cross Metathesis Full Text HTML PDF ( kb) A Novel Bifunctional Ligand–Metal Combination for Asymmetric Hydrogenation Tetrasubstituted Olefin Synthesis via a Halogen-Induced 1,2-Silyl Migration Full Text HTML PDF ( kb).
Tetrahedron This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog. Publications. Here is a full list of papers, book chapters and patents from the Laschat research group.
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An indolinooxazolidine tagged N-heterocyclic carbene Ru olefin metathesis catalyst was synthesized and the molecular structure of this new Ru complex was determined by single crystal X-ray diffraction.