68972-93-0

Upstream product

• 821-06-7 (E)-1,4-dibromobutene 
• 100-51-6 benzyl alcohol 
• 821-11-4 trans-butene-1,4-diol 
• 100-39-0 benzyl bromide 
• 68972-96-3 (Z)-1,4-dibenzyloxy-2-butene 
• 100-44-7 benzyl chloride 
• 14593-43-2 benzyl allyl ether 
• 136458-56-5 2,3-bis((benzyloxy)methyl)oxirane 
• 162369-37-1 2,3-bis((benzyloxy)methyl)thiirane 

Downstream Products

• 91604-41-0 (R,R)-1,4-dibenzylthreitol 
• 69010-01-1 (2R*,3S*)-1,4-bis(benzyloxy)butane-2,3-diol 
• 132398-71-1 (2R,3R)-2,3-Bis-benzyloxymethyl-cyclopropanecarboxylic acid ethyl ester 
• 70677-91-7 1,4-bis(benzyloxy)-3-phenylseleno-2-butanone 
• 60656-87-3 benzyloxyacetoaldehyde 
• 1271145-22-2 (2R*,3S*)-2,3-bis(benzyloxymethyl)-1,4-dioxane 
• 1309474-32-5 (+)-(S)-(((2-vinyloctyl)oxy)methyl)benzene 
• 167841-04-5 2-benzyloxymethyl-6-methyl-2,3-dihydro-4H-pyran-4-one 
• 68973-05-7 (2R*,3S*)-2,3-bis((benzyloxy)methyl)oxirane 
• 132398-78-8 9-((2R,3R)-2,3-Bis-benzyloxymethyl-cyclopropyl)-6-chloro-9H-purine 
• 132398-79-9 9-((2R,3R)-2,3-Bis-benzyloxymethyl-cyclopropyl)-9H-purin-6-ylamine 

Relevant academic research and scientific papers

Synthesis of 5-thiodidehydropyranylcytosine derivatives as potential anti-HIV agents

As a part of our ongoing efforts to identify new anti-HIV agents, a 5′-thiopyrano-nucleoside derivative 4, designed based on 4′-thioD4C 1 and cyclohexenylnucleoside 3, was synthesized. The dihydrothiopyran skeleton of 4 was constructed by the ring closing metathesis of 21 which was synthesized from but-2-yne-1,4-diol. After converting the protecting group from MOM to TBS followed by oxidation, a Pummerer-type thioglycosylation reaction of 24 with persilylated uracil gave the desired 5-thiodihydrothiopyranyluracils 25 and 26 as a mixture of anomers. The conversion of 25 to a cytosine derivative and subsequent deprotection gave a 5-thiodidehydropyranosylcytosine derivative 4 in good yield. The anti-HIV activity of 4 was also evaluated.

The synthesis of the 2, 3-difluorobutan-1, 4-diol diastereomers

The diastereoselective synthesis of fluorinated building blocks that contain chiral fluorine substituents is of interest. Here we describe optimisation efforts in the synthesis of anti-2, 3-difluorobutane-1, 4-diol, as well as the synthesis of the corresponding syn-diastereomer. Both targets were synthesised using an epoxide opening strategy.

Highly Z-selective olefins metathesis

The present invention relates generally to catalysts and processes for the Z-selective formation of internal olefin(s) from terminal olefin(s) via homo-metathesis reactions.

Isolation of pure disubstituted e olefins through mo-catalyzed Z-selective ethenolysis of stereoisomeric mixtures

Monoaryloxide-pyrrolide (MAP) complexes of molybdenum were employed for the selective ethenolysis of 1,2-disubstituted Z olefins in the presence of the corresponding E olefins. Reactions were performed in the presence of 0.02-3.0 mol % catalyst at 22 °C under 20 atm ethylene. We have demonstrated that the Z isomer of an easily accessible E:Z mixture can be destroyed through ethenolysis and the E alkene thereby isolated readily in high yield and exceptional stereoisomeric purity.

E/Z product distribution in the metathesis of allyl alcohol derivatives with a first generation ruthenium-based catalyst

Based on experiments with four simple derivatives of allyl alcohol, it has been shown that the product of cross-metathesis as mediated by a 'first generation' ruthenium catalyst increases in its proportion of the E-isomer as the reaction progresses. This increase is due to equilibration, which is also mediated by the ruthenium catalyst.

HIGHLY Z-SELECTIVE OLEFINS METATHESIS

The present invention relates generally to catalysts and processes for the Z-selective formation of internal olefin(s) from terminal olefin(s) via homo-metathesis reactions.

Synthesis of 3,4-Ethylenedioxythiophene (EDOT) from (Z)-but-2-ene-1,4-diol or but-2-yne-1,4-diol

3,4-Ethylenedioxythiophene (EDOT) was synthesized from commercially available (Z)-but-2-ene-1,4-diol or but-2-yne-1,4-diol using epoxidation, etherification, and thiophene formation. The Japan Institute of Heterocyclic Chemistry.

In situ generated bulky palladium hydride complexes as catalysts for the efficient isomerization of olefins. Selective transformation of terminal alkenes to 2-alkenes

Application of an in situ generated bulky palladium(II) hydride catalyst obtained from a 1:1:1 mixture of Pd(dba)2, P(tBu)3, and isobutyryl chloride provides an efficient protocol for the isomerization and migration of a variety of olefins. In addition to the isomerization of (Z)- to (E)-olefins, the conjugative migration of allylbenzenes, allyl ethers, and amines was effectively achieved in near-quantitative yields and with excellent functional group tolerance. Catalyst loadings in the range of 0.5-1.0 mol % were typically applied, but even loadings as low as 0.25 mol % could be achieved when the reactions were performed under neat conditions. More interestingly, the investigated catalyst proved to be selective for converting terminal alkenes to 2-alkenes. This one-carbon migration process for monosubstituted olefins provides an alternative catalyst, which bridges the gap between the allylation and propenylation/vinylation protocols. Several substrates, including homoallylic alcohols and amines, were selectively transformed into their corresponding 2-alkenes, and examples using enantiomerically enriched substrates provided products without epimerization at the allylic stereogenic carbon centers. Finally, some mechanistic investigations were undertaken to understand the nature of the active in situ generated Pd-H catalyst. These studies revealed that the catalytic system is highly dependent on the large steric demand of the P(tBu)3 ligand. The use of an alternative ligand, cataCXium PinCy, also proved effective for generating an active catalyst, and it was demonstrated in some cases to display better selectivity for the one-carbon shifts of terminal olefins. A possible intermediate involved in the preparation of the active catalyst was characterized by its single-crystal X-ray structure, which revealed a monomeric tricoordinated palladium(II) acyl complex, bearing a chloride ligand.

Highly Z-selective metathesis homocoupling of terminal olefins

(Chemical Equation Presented) Mo and W MonoAryloxide-Pyrrolide (MAP) olefin metathesis catalysts can couple terminal olefins to give as high as >98% Z-products in moderate to high yields with as little as 0.2% catalyst. Results are reported for 1-hexene, 1-octene, allylbenzene, allyltrimethylsilane, methyl-10-undecenoate, methyl-9-decenoate, allylB(pinacolate), allylOBenzyl, allylNHTosyl, and allylNHPh. It is proposed that high Z-selectivity is achieved because a large aryloxide only allows metallacyclobutanes to form that contain adjacent cis substituents and because isomerization of Z-product to E-product can be slow in that same steric environment.

First evidence for the formation of a geminal dizinc carbenoid: A highly stereoselective synthesis of 1,2,3-Substituted cyclopropanes

Significant amounts of novel gem-dizinc carbenoids (RZnCHIZnR) are formed when diethylzinc is mixed with iodoform in CH2Cl2 at 0 °C. This reagent was shown to be effective in the cyclopropanation of butenediol derivatives to generate