Various substituted Dispiro [pyrrolo-piperazino-oxindole] have been synthesized by utilizing a simple and efficient two-step synthetic protocol Grubbs metathesis in dichloromethane at 40°C. The structures relative stereochemistry of the cycloadduct were confirmed single-crystal X-ray diffraction, 1H 13C NMR spectroscopy, mass spectrometry.
 
 Keywords: Hexahydro-diazecane-dione, Metat...

Dicarboxylic acids derived from plant oils are attractive intermediates for the synthesis of polymer materials. Similar to polyethylene, the incorporation of long methylene sequences enables polymer crystallization and renders polyesters hydrophobic. Long-chain aliphatic polyesters that incorporate the full length of the plant oil methylene sequences possess high melting points (Tm > 100 °C) an...

The first application of olefin cross-metathesis with vinylchlorins and vinylporphyrins using a "second generation" Grubbs' catalyst is reported. Cross-metathesis products were obtained in good yields with high E-stereoselectivity.

This communication describes the total synthesis of the marine polyether toxin, gambierol. This work couples our iterative C-glycoside/enol ether-olefin metathesis strategy to the subunits with a unique olefin metathesis/carbonyl olefination reaction to bring the subunits together.

A novel synthetic route to spirocyclic thiazolidinediones is reported by utilizing ring-closing metathesis (RCM). A selective cross metathesis (CM) of N-allyl azaspiro derivatives with different olefins has been demonstrated to prepare substituted azaspiro-[4.4]nonenediones. The X-ray crystal structure of a spirocyclic thiazolidinedione dimer is described, which has been prepared in two steps f...

Recombinant peptide synthesis allows for large-scale production of peptides with therapeutic potential. However, access to dicarba peptidomimetics via sidechain-deprotected sequences becomes challenging exposed Lewis basicity presented by amine and sulfur-containing residues. Presented here is a combination strategies which can be used deactivate coordinative residues achieve high-yielding Ru-c...

Metallacyclobutanes are an important class of organometallic intermediates, due to their role in olefin metathesis. They can have either planar or puckered rings associated with characteristic chemical and physical properties. Metathesis active metallacyclobutanes have short M-Cα/α' and M···Cβ distances, long Cα/α'-Cβ bond length, and isotropic 13C chemical shifts for both early d0 and late d4 ...

This paper presents a computational analysis of metathesis patterns that distinguishes three categories of metathesis that differ in their computational complexity. These categories are local metathesis, bounded long distance metathesis, and unbounded long distance metathesis. Using the formalism of finite state automata, it is established that the first two categories are subsequential, while ...

Judeo-Spanish (JS) denotes those varieties of Spanish preserved by the Sephardic Jews who were expelled from Spain in 1492 and have emigrated throughout Europe, North Africa, the Middle East, and the United States. Some descriptions of JS emphasize its conservative, archaic nature, highlighting its similarities to Old Spanish (OS), while other research points up the novel characteristics that d...

The evaluation of ruthenium olefin metathesis catalysts 4-6 bearing cyclic (alkyl)(amino)carbenes (CAACs) in the cross-metathesis of cis-1,4-diacetoxy-2-butene (7) with allylbenzene (8) and the ethenolysis of methyl oleate (11) is reported. Relative to most NHC-substituted complexes, CAAC-substituted catalysts exhibit lower E/Z ratios (3:1 at 70% conversion) in the cross-metathesis of 7 and 8. ...