17814-72-1

Upstream product

• 1002-28-4 3-hexyn-1-ol 
• 87498-17-7 methyl hex-3-ynoate 
• 81981-05-7 methyl 3,4-hexadienoate 
• 93604-63-8 hex-3-ynenitrile 
• 16400-32-1 1-bromo-pent-2-yne 

Downstream Products

• 2313-01-1 5-ethyl-2(3H)-furanone 
• 1383445-16-6 (Z)-diethyl 1-benzyl-5-oxo-3-propylidenepyrrolidine-2,2-dicarboxylate 
• 1351364-81-2 (E)-diethyl 1-benzyl-5-oxo-3-propylidenepyrrolidine-2,2-dicarboxylate 
• 1374601-09-8 3a-ethyl-4-(phenylamino)-2,3,3a,4-tetrahydropyrrolo[1,2-a]quinazoline-1,5-dione 
• 1374601-10-1 7-bromo-3a-ethyl-4-(phenylamino)-2,3,3a,4-tetrahydropyrrolo[1,2-a]-quinazoline-1,5-dione 
• 13894-61-6 methyl (E)-hex-3-enoate 
• 1775-43-5 (Z)-3-hexenoic acid 
• 1577-18-0 (E)-3-hexenoic acid 

Relevant academic research and scientific papers

Atom-Economical Cross-Coupling of Internal and Terminal Alkynes to Access 1,3-Enynes

Selective carbon-carbon (C-C) bond formation in chemical synthesis generally requires prefunctionalized building blocks. However, the requisite prefunctionalization steps undermine the overall efficiency of synthetic sequences that rely on such reactions, which is particularly problematic in large-scale applications, such as in the commercial production of pharmaceuticals. Herein, we describe a selective and catalytic method for synthesizing 1,3-enynes without prefunctionalized building blocks. In this transformation several classes of unactivated internal acceptor alkynes can be coupled with terminal donor alkynes to deliver 1,3-enynes in a highly regio- and stereoselective manner. The scope of compatible acceptor alkynes includes propargyl alcohols, (homo)propargyl amine derivatives, and (homo)propargyl carboxamides. This method is facilitated by a tailored P,N-ligand that enables regioselective addition and suppresses secondary E/Z-isomerization of the product. The reaction is scalable and can operate effectively with as low as 0.5 mol % catalyst loading. The products are versatile intermediates that can participate in various downstream transformations. We also present preliminary mechanistic experiments that are consistent with a redox-neutral Pd(II) catalytic cycle.

Tandem Regioselective Hydroformylation-Hydrogenation of Internal Alkynes Using a Supramolecular Catalyst

New supramolecular ligands containing an acyl guanidine function were designed based on the strategy of increasing the π-acceptor ability of phosphine ligands by introducing electron-withdrawing groups. By applying this novel catalytic system, a general protocol for the Rh-catalysed hydroformylation-hydrogenation of unsymmetrical internal alkynes, functionalized with a carboxylic acid, was found to furnish aliphatic aldehydes in high regio- and chemoselectivities. Control experiments confirm the enzyme-like supramolecular catalyst mode of action.

Palladium(II)-Catalyzed Directed anti-Hydrochlorination of Unactivated Alkynes with HCl

A regioselective anti-hydrochlorination of unactivated alkynes is reported. The reaction utilizes in situ generated HCl as the source of both the Cl- and H+ and is catalyzed by palladium(II) acetate, with loadings as low as 25 ppm. Removable picolinamide and 8-aminoquinoline bidentate directing groups are used to control the regioselectivity of the chloropalladation step and stabilize the resulting alkenylpalladium(II) intermediate for subsequent protodepalladation. This method provides access to a broad array of substituted alkenyl chlorides in excellent yields and with high regioselectivity. The products from this transformation were successfully derivatized via Stille coupling to a variety of trisubstituted alkene products. Reaction progress kinetic analysis was performed, shedding light on a possible mechanism for this catalytic process.

Synthesis of highly substituted γ-butyrolactones by a gold-catalyzed cascade reaction of benzyl esters

Easily accessible benzylic esters of 3-butynoic acids in a gold-catalyzed cyclization/rearrangement cascade reaction provided 3-propargyl γ-butyrolactones with the alkene and the carbonyl group not being conjugated. Crossover experiments showed that the formation of the new C-C bond is an intermolecular process. Initially propargylic-benzylic esters were used, but alkyl-substituted benzylic esters worked equally well. In the case of the propargylic- benzylic products, a simple treatment of the products with aluminum oxide initiated a twofold tautomerization to the allenyl-substituted g-butyrolactones with conjugation of the carbonyl group, the olefin, and the allene. The synthetic sequence can be conducted stepwise or as a one-pot cascade reaction with similar yields. Even in the presence of the gold catalyst the new allene remains intact.

Highly enantioselective direct vinylogous Michael addition of γ-butenolide to enals

An unprecedented and simple direct vinylogous addition of deconjugated butenolide to enals has been developed in excellent stereoselectivities (>95% ee), with Aminal-PYrrolidine (APY) catalyst. This methodology allows for the efficient preparation of comp

Asymmetric synthesis of 1-alkynylcyclopropane-1-carboxylates

Dirhodium tetrakis(S-(N-dodecylbenzenesulfonyl)prolinate) (Rh2S-DOSP4) catalyzed decomposition of methyl alkynyldiazoacetates in the presence of alkenes results in highly diastereoselective and enantioselective cyclopropanations. (C) 2000 Published by Elsevier Science Ltd.