13120-47-3

Upstream product

• 127-66-2 2-Phenyl-3-butyn-2-ol 
• 17343-73-6 (2,2-dibromo-1-methylcyclopropyl)benzene 
• 536-74-3 phenylacetylene 
• 100-51-6 benzyl alcohol 
• 120-72-9 indole 
• 13829-77-1 3-(trimethylsilyl)-1-phenyl-2-propyn-1-one 
• 93523-49-0 trimethyl(3-phenylbut-3-en-1-yn-1-yl)silane 
• 65050-53-5 1-methoxy-buta-1,2,3-triene 

Relevant academic research and scientific papers

Enantioselective Construction of Quaternary Stereogenic Centers by the Addition of an Acyl Anion Equivalent to 1,3-Dienes

We report the enantioselective formation of quaternary stereogenic centers by the intermolecular addition of malononitrile, an acyl anion equivalent, and related pronucleophiles to several 1,3-disubstituted acyclic 1,3-dienes in the presence of a Pd-PHOX catalyst. Products are obtained in up to 88% yield and 99:1 er and in most cases are formed as a single regioisomer. The products' malononitrile unit undergoes oxidative functionalization to afford β,γ-unsaturated carbonyls bearing internal olefins and α-quaternary stereogenic centers.

Heterogeneous Acid-Catalyzed Racemization of Tertiary Alcohols

Tertiary alcohols are important structural motifs in natural products and building blocks in organic synthesis but only few methods are known for their enantioselective preparation. Chiral resolution is one of these approaches that leaves one enantiomer (50 % of the material) unaffected. An attractive method to increase the efficiency of those resolutions is to racemize the unaffected enantiomer. In the present work, we have developed a practical racemization protocol for tertiary alcohols. Five different acidic resin materials were tested. The Dowex 50WX8 was the resin of choice since it was capable of racemizing tertiary alcohols without any byproduct formation. Suitable solvents and a biphasic system were investigated, and the optimized system was capable of racemizing differently substituted tertiary alcohols.

Synthesis, structural characterization and catalytic activity of indenyl complexes of ruthenium bearing fluorinated phosphine ligands

The synthesis, characterization and catalytic activity of new ruthenium complexes of fluorinated triarylphosphines is described. The new ruthenium complexes [RuCl(ind)(PPh3){P(p-C6H4CF3)3}] and [RuCl(ind)(PPh3){P(3,5-C6H3(CF3)2)3}] were synthesized in 57% and 24% isolated yield, respectively, by thermal ligand exchange of [RuCl(ind)(PPh3)2], where ind = indenyl ligand η5-C9H7?. The electronic and steric properties of the new complexes were studied through analysis of the X-ray structures and through cyclic voltammetry. The new complexes [RuCl(ind)(PPh3){P(p-C6H4CF3)3}] and [RuCl(ind)(PPh3){P(3,5-C6H3(CF3)2)3}] and the known complex [RuCl(ind)(PPh3)2}] differed only slightly in their steric properties, as seen from comparison of bond lengths and angles associated with the ruthenium center. As determined by cyclic voltammetry, the redox potentials of [RuCl(ind)(PPh3){P(p-C6H4CF3)3}] and [RuCl(ind)(PPh3){P(3,5-C6H3(CF3)2)3}] are +0.173 and + 0.370 V vs. Cp2Fe0/+, respectively, which are substantially higher than that of [RuCl(ind)(PPh3)2] (?0.023 V). After activation through chloride abstraction, the new complexes are catalytically active in the etherification of propargylic alcohols (8–24 h at 90 °C in toluene, 1–2 mol% catalyst loading, 29–61% isolated yields). As demonstrated by a comparative study for a test reaction, the three precursor complexes [RuCl(ind)(PPh3){P(p-C6H4CF3)3}], [RuCl(ind)(PPh3){P(3,5-C6H3(CF3)2)3}] and [RuCl(ind)(PPh3)2}] differed only slightly in catalytic activity.

Gold-Catalyzed Imination/Mannich Reaction Cascades of 3-En-1-ynamides with Anilines and Aldehydes to Enable 1,5-Nitrogen Functionalizations

Gold-catalyzed imination/Mannich reaction cascades on readily available 3-en-1-ynamides enable the diastereoselective synthesis of 1,5-iminoamino compounds in a one-pot operation. The reactions work well with diversified 3-en-1-ynamides, aldehydes and anilines with good to excellent diastereoselectivities. Our control experiments indicate gold-catalyzed aminations of 3-en-1-ynamides to yield α-imino allylgold intermediates that react subsequently with iminiums to implement the Mannich reactions stereoselectively. The reactions proceed with anti-selectivity for those 3-en-1-ynamides bearing acyclic alkenes whereas syn-selectivity is seen for their cycloalkene-based analogues. An open-transition state can satisfactorily rationalize these observed stereoselectivities based on an antiperiplanar conformation.

Construction of Chiral Tri- and Tetra-Arylmethanes Bearing Quaternary Carbon Centers: Copper-Catalyzed Enantioselective Propargylation of Indoles with Propargylic Esters

Copper-catalyzed enantioselective propargylation of indoles with propargylic esters and sequential Huisgen cycloaddition with azides lead to the construction of chiral triarylmethanes, bearing a quaternary carbon center, with high to excellent enantioselectivities. The result described herein can be used in the enantioselective preparation of a tetraarylmethane.

Reactions of vinylidenecyclopropanes with diphenyl diselenide in the presence of AIBN and thermally-induced further transformations

In conclusion, we have developed a novel tandem reaction of VDCPs 1 with PhSeSePh to give the corresponding bicyclo[3.1.0]hexane derivatives 4 in good yields in the presence of AIBN, which could undergo a thermal-induced radical 1,4-hydrogen shift through

Borostannylation of alkynes and enynes. Scope and limitations of the reaction and utility of the adducts

The utility of the hetero-bismetallating reagent 1,3-dimethyl-2- trimethylstannyl-2-bora-1,3-diazacyclopentane (1) has not been fully realized because of the hydrolytic instability of the products derived from catalyzed vicinal syn-additions to alkynes. The isolation of a variety of such adducts derived from alkynes (and also from hitherto unreported additions to 1,3-enynes) as stable boron pinacolates is reported. Examples of the applications of resulting products in tandem cross-coupling reactions and as dienes in Diels-Alder reactions are illustrated.

Acid-catalyzed cascade ring-opening and addition reactions of arylvinylcyclopropenes with α, β-unsaturated substrates, scope and limitations

Catalyzed by Al(III) catalyst, arylvinylcyclopropenes react with a,/3-unsaturated substrates smoothly to produce the Diels-Alder adducts in moderate to good yields through a cascade ring-opening reaction/ Diels-Alder cycloaddition. On the other hand, stro

Isomerization of propargylic alcohols into α,β-unsaturated carbonyl compounds catalyzed by the sixteen-electron allyl-ruthenium(II) complex [Ru(η3-2-C3H4Me)(CO)(dppf)] [SbF 6]

The 16-e- (η3-allyl)-ruthenium(II) complex [Ru(η3-2-C3H4Me)(CO)(dppf)][SbF 6] is an efficient catalyst for the regioselective isomerization of terminal propargylic alcohols HC≡CCR1R2(OH) into α,β-unsaturated aldehydes R1R2C=CHCHO or ketones R3R4C=C(R1)COMe (if R2 = CHR3R4) under mild conditions. This complex has been also used as catalyst for the preparation of conjugated 1,3-enynes via dehydration of propargylic alcohols.

Ruthenium-catalyzed propargylic substitution reactions of propargylic alcohols with oxygen-, nitrogen-, and phosphorus-centered nucleophiles

The scope and limitations of the ruthenium-catalyzed propargylic substitution reaction of propargylic alcohols with heteroatom-centered nucleophiles are presented. Oxygen-, nitrogen-, and phosphorus-centered nucleophiles such as alcohols, amines, amides, and phosphine oxide are available for this catalytic reaction. Only the thiolate-bridged diruthenium complexes can work as catalysts for this reaction. Results of some stoichiometric and catalytic reactions indicate that the catalytic propargylic substitution reaction proceeds via an allenylidene complex formed in situ, whereby the attack of nucleophiles to the allenylidene Cγ atom is a key step. Investigation of the relative rate constants for the reaction of propargylic alcohols with several para-substituted anilines reveals that the attack of anilines on the allenylidene Cγ atom is not involved in the rate-determining step and rather the acidity of conjugated anilines of an alkynyl complex, which is formed after the attack of aniline on the C γ atom, is considered to be the most important factor to determine the rate of this catalytic reaction. The key point to promote this catalytic reaction by using the thiolate-bridged diruthenium complexes is considered to be the ease of the ligand exchange step between a vinylidene ligand on the diruthenium complexes and another propargylic alcohol in the catalytic cycle. The reason why only the thiolate-bridged diruthenium complexes promote the ligand exchange step more easily with respect to other monoruthenium complexes in this catalytic reaction should be that one Ru moiety, which is not involved in the allenylidene formation, works as an electron pool or a mobile ligand to another Ru site. The catalytic procedure presented here provides a versatile, direct, and one-step method for propargylic substitution of propargylic alcohols in contrast to the so far well-known stoichiometric and stepwise Nicholas reaction.