100330-45-8

Upstream product

• 99902-35-9 5-phenylpent-1-yn-3-ol 
• 108-24-7 acetic anhydride 
• 104-53-0 3-phenyl-propionaldehyde 
• 110211-31-9 Acetic acid 1-phenethyl-3-trimethylsilanyl-prop-2-ynyl ester 
• 4301-14-8 acetylenemagnesium bromide 
• 75-36-5 acetyl chloride 
• 140149-77-5 5-phenyl-1-trimethylsilylpent-1-yn-3-ol 

Downstream Products

• 100330-37-8 Acetic acid 2,4-dioxo-1-phenethyl-pentyl ester 
• 1026082-30-3 4-oxo-1-phenylpentan-3-yl acetate 
• 143140-90-3 2-(1-acetoxy-3-(phenyl)propyl)-1,3-butadiene 
• 1378870-87-1 (3-ethynylhex-5-en-1-yl)benzene 
• 929606-19-9 (R)-5-phenylpent-1-yn-3-yl acetate 
• 1609456-38-3 4,4,5,5-tetramethyl-2-(5-phenylpenta-1,2-dien-1-yl)-1,3,2-dioxaborolane 
• 104367-27-3 hepta-3,4-diene-1,7-diyldibenzene 
• 104367-28-4 (7-methylocta-3,4-dien-1-yl)benzene 
• 1823-14-9 5-phenyl-1-pentyne 
• 40339-21-7 penta-3,4-dienyl-benzene 
• 1436409-05-0 C₂₁H₂₈O₂ 

Relevant academic research and scientific papers

Rhodium-Catalyzed Parallel Kinetic Resolution of Racemic Internal Allenes Towards Enantiopure Allylic 1,3-Diketones

A rare case of a parallel kinetic resolution of racemic 1,3-disubstituted allenes by means of a rhodium-catalyzed addition to 1,3-diketones furnishing enantiopure allylic 1,3-diketones is described. Mechanistic experiments demonstrate that the different allene enantiomers react in parallel to either the diastereomeric E- or Z-allylic 1,3-diketones with the same absolute configuration of the newly formed stereogenic center. A broad substrate scope demonstrates the synthetic utility of this new method.

Palladium- and Rhodium-Catalyzed Dynamic Kinetic Resolution of Racemic Internal Allenes Towards Chiral Pyrazoles

A complementing Pd- and Rh-catalyzed dynamic kinetic resolution (DKR) of racemic allenes leading to N-allylated pyrazoles is described. Such compounds are of enormous interest in medicinal chemistry as certified drugs and potential drug candidates. The new methods feature high chemo-, regio- and enantioselectivities aside from displaying a broad substrate scope and functional group compatibility. A mechanistic rational accounting for allene racemization and trans-alkene selectivity is discussed.

Borylation of propargylic substrates by bimetallic catalysis. Synthesis of allenyl, propargylic, and butadienyl bpin derivatives

Bimetallic Pd/Cu and Pd/Ag catalytic systems were used for borylation of propargylic alcohol derivatives. The substrate scope includes even terminal alkynes. The reactions proceed stererospecifically with formal S N2′ pathways to give allenyl boronates. Opening of propargyl epoxides leads to 1,2-diborylated butadienes probably via en allenylboronate intermediate.

Stereocontrol in palladium-catalyzed propargylic substitutions: Kinetic resolution to give enantioenriched 1,5-enynes and propargyl acetates

Kinetic resolution during the catalytic allyl-propargyl cross-coupling with chiral starting materials can be accomplished with a chiral palladium catalyst. These reactions offer ready access to enantiomerically enriched enyne products from simple, readily

Construction of 1,5-enynes by stereospecific Pd-catalyzed allyl-propargyl cross-couplings

The palladium-catalyzed cross-coupling of chiral propargyl acetates and allyl boronates delivers chiral 1,5-enynes with excellent levels of chirality transfer and can be applied across a broad range of substrates.

Enantioselective copper-catalysed propargylic substitution: Synthetic scope study and application in formal total syntheses of (+)-anisomycin and (-)-cytoxazone

A copper catalyst with a chiral pyridine-2,6-bisoxazoline (pybox) ligand was used to convert a variety of propargylic esters with different side chains (R=Ar, Bn, alkyl) into their amine counterparts in very high yields and with good enantioselectivities (up to 90% enantiomeric excess (ee)). Different amine nucleophiles were applied in the reactions and the highest enantioselectivities were obtained for aniline and its analogues. Interestingly, some carbon nucleophiles could also be used and with indoles excellent ee values were obtained (up to 98% ee). The versatility of the propargylic amines obtained was demonstrated by their further elaboration to formal total syntheses of the antibiotic (+)-anisomycin and the cytokine modulator (-)-cytoxazone. Copyright

DBU-promoted facile, chemoselective cleavage of acetylenic TMS group

Acetylenic trimethylsilyl (TMS) groups were efficiently removed using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). With either 1.0 or even 0.1 equivalents of DBU, smooth desilylation of various terminal acetylenic TMS groups was accomplished selectively in the presence of alkyl silyl ethers and other base-labile groups. Furthermore, more sterically hindered terminal acetylenic silyl groups such as TBDMS and TIPS remained intact under these conditions. Georg Thieme Verlag Stuttgart.

Hydroxyl-directed intermolecular ketone-olefin couplings promoted by SmI2

SmI2-promoted intermolecular ketone-olefin couplings are facilitated and stereocontrolled by hydroxyl groups incorporated within the starting materials. For example, the SmI2-induced ketone-olefin coupling reactions of α-hydroxy ketone 5 with ethyl acrylate, acrylonitrile, ethyl crotonate, and 2(5H)-furanone proceeded with high stereocontrol to afford the syn-1,2-diol products 6-9 in good yields. Excellent diastereoselectivity was achieved in the reductive couplings of β-hydroxy aldehyde 21 and erythro-β-hydroxy ketone 24 with acrylonitrile using SmI2, to produce the anti-1,3-diols 22 and 25 in good yields. The sense of the stereoselectivity was in full accord with a chelation-control model. In the proposed model, the stereochemistry of the reaction product is explained by assuming that a cyclic ketyl radical is generated during the initial single-electron reduction by SmI2. This radical species results from the chelation of the Sm(III) cation, attached to the ketyl radical, with the hydroxyl group.

Samarium(II) Iodide Promoted Intermolecular Ketone-Olefin Couplings Chelation-Controlled by α-Hydroxyl Groups

The hydroxyl group directed intermolecular ketone-olefin coupling reactions induced by SmI2 between α-hydroxyl ketones and α,β-unsaturated esters occurred with excellent stereochemical control about the newly formed asymmetric centers.