Intramolecular Ring-closing Metathesis Research Articles

Toward the Synthesis of the Antibiotic Branimycin: Novel Approaches to Highly Substituted cis‐Decalin Systems

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Stereoselective Synthesis of Nuphar Quinolizidine Alkaloid, (‐)‐Deoxynupharidine.

A stereoselective synthetic route to Nuphar quinolizidine alkaloid, (−)-deoxynupharidine, was established by employing reductive carbon–nitrogen bond cleavage, followed by simultaneous recyclization of a proline derivative with samarium diiodide, and an intramolecular ring-closing metathesis, as the key steps.

Synthesis of streptorubin B core

A straightforward synthesis of streptorubin B core structure has been established starting from trans-4-hydroxyproline. The core structure of streptorubin B is constructed in an intramolecular ring-closing metathesis as the key step.

Stereoselective synthesis of Nuphar quinolizidine alkaloid, (−)-deoxynupharidine

A stereoselective synthetic route to Nuphar quinolizidine alkaloid, (−)-deoxynupharidine, was established by employing reductive carbon–nitrogen bond cleavage, followed by simultaneous recyclization of a proline derivative with samarium diiodide, and an intramolecular ring-closing metathesis, as the key steps.

Synthesis and structure of symmetrical bicyclic hexapeptides bridged by metathesis reaction.

[structure: see text] Bicyclic hexapeptides 1a-c were synthesized via an intramolecular ring-closing metathesis reaction on solid phase followed by an N- to C-terminal cyclization in solution. Structural elucidation showed that these compounds assumed a C2-symmetrical structure with two beta-turns. The trans-ethylene plane was found to occupy two positions in rapid interconversion. One of the bicyclic hexapeptides crystallized with five water molecules, which made an arch above the ethylene group.

Ring‐Closing Metathesis in the Synthesis of Cyclic α‐Amino Acids

AbstractFor Abstract see ChemInform Abstract in Full Text.

Ring-Closing Metathesis in the Synthesis of Cyclic -Amino Acids

The review summarizes recent advances in the synthesis of cyclic α-amino acids via intramolecular ring-closing metathesis of dienes and enynes.

Synthesis of Functionalized Olefins by Cross and Ring-Closing Metatheses

The generation of olefins with electron-withdrawing functionality, such as α,β-unsaturated aldehydes, ketones, and esters, remains a difficult task in organic chemistry. A practical method to approach this problem would involve olefin metathesis, utilizing well-defined alkylidenes such as ((CF_3)_2MeCO)_2(ArN)Mo CH(t-Bu) (1) and (Pcy_3)_2Cl_2Ru CHPh (2). However, the generation of olefins with vinylic functionality through the use of cross-metathesis (CM) has met with limited success. In one of the few reports of this reaction, Crowe and Goldberg demonstrated that acrylonitrile participated in cross-metathesis reactions with a variety of terminal olefins. Other π-conjugated olefins, such as enones and enoic esters, were not functional group compatible with alkylidene 1 and failed to react with 2 in cross-metathesis. Recently, the highly active ruthenium-based olefin metathesis catalyst 3, which contains a 1,3-dimesityl-4,5-dihydro-imidazol-2-ylidene ligand, was found to efficiently catalyze the cross-metathesis of 1,1-geminally disubstituted olefins.7 Because ruthenium alkylidene 3 displayed unique activity toward previously metathesis-inactive substrates, we decided to investigate the metathesis of α-functionalized olefins. In this communication, we report the single-step synthesis of α-functionalized olefins by intermolecular cross-metathesis and intramolecular ring-closing metathesis using ruthenium alkylidene 3.

High‐Yield Synthesis of [2] Catenanes by Intramolecular Ring‐Closing Metathesis

High‐Yield Synthesis of [2] Catenanes by Intramolecular Ring‐Closing Metathesis