262586-92-5

Upstream product

• 16520-62-0 4-Phenyl-1-butyne 
• 2043-61-0 cyclohexanecarbaldehyde 

Relevant academic research and scientific papers

Enantioselective Alkyne Addition to Aliphatic, Aromatic, and Vinyl Aldehydes Using Zn, iPrI, H8BINOL, and Ti(OiPr)4

A new catalytic system based on the readily available Zn, iPrI, H8BINOL, and Ti(OiPr)4 has been developed which avoids the use of pyrophoric ZnEt2. It can effectively catalyze the reaction of various terminal alkynes with aromatic, aliphatic, and vinyl aldehydes to generate chiral propargylic alcohols at room temperature with up to 98% yield and 98% enantiomeric excess. This new system signifciantly expands the substrate scope of the previously reported system using Zn, EtI, BINOL, and Ti(OiPr)4.

Catalytic asymmetric synthesis of chiral propargylic alcohols for the intramolecular Pauson-Khand cycloaddition

Several methods for the catalytic asymmetric alkyne addition to aldehydes are used to prepare the propargylic alcohol-based chiral en-ynes. Protection of the propargylic alcohols with either an acetyl or a methyl group allows the resulting en-ynes to undergo the intramolecular Pauson-Khand reaction to form the corresponding optically active 5,5- and 5,6-fused bicyclic products with high diastereoselectivity and high enantiomeric purity. In the major product, the propargylic substituent and the bridgehead hydrogen are cis with respect to each other on the fused bicyclic rings. The enantiomeric purity of the propargylic alcohols generated from the asymmetric alkyne addition is maintained in the cycloaddition products. The allylic ethers of the chiral propargylic alcohols are prepared which can also undergo the highly diastereoselective Pauson-Khand cycloaddition with retention of the high enantiomeric purity. This study has shown that the size of the substituents at the propargylic position as well as on the alkyne is important for the diastereoselectivity with the greater bulkiness of the substituents giving higher diastereoselectivity.

Stereochemistry of intermolecular oxypalladation: PdII-catalyzed 1,3-chirality transfer reaction of chiral allylic alcohol with methanol

(Chemical Equation Presented) The intermolecular oxypalladation of chiral nonracemic allylic alcohols (S)-1, (R)-1, and (R)-3 in methanol gave chiral nonracemic methyl allyl ethers (S)-2 and/or (R)-2 with excellent selectivity. The reaction induced the 1,

3,3′-anisyl-substituted BINOL, H4BINOL, and H 8BINOL ligands: Asymmetric synthesis of diverse propargylic alcohols and their ring-closing metathesis to chiral cycloalkenes

(Chemical Equation Presented) A series of optically active BINOL, H 4BINOL, and H8BINOL derivatives were prepared. These compounds in combination with ZnEt2 and Ti(OiPr) 4 were used to catalyze the asymmetric reaction of alkynes with aldehydes to generate chiral propargylic alcohols at room temperature. Through this comparative study, a 3,3′-bisanisyl-substituted H8BINOL (S)-7 was found to be a generally enantioselective catalyst for the reaction of structurally diverse terminal alkynes with a variety of aldehydes. It catalyzed the reactions of alkyl propiolates with 88-99% ee; the reactions of phenylacetylene with 81-87% ee; the reactions of 4-phenyl-1-butyne, an alkyl alkyne, with 77-89% ee; and the reactions of trimethylsilylacetylene with 92-97% ee. The optically active propargylic alcohols generated from this catalytic asymmetric alkyne addition were observed to undergo efficient ring-closing-metathesis (RCM) reaction in the presence of the Grubbs II catalyst to produce chiral cycloalkenes. It was further found that some of the chiral propargylic alcohols underwent a highly chemoselective tandem RCM hydrogenation reaction with retention of the enantiomeric purity. 2009 American Chemical Society.

Carbohydrate-derived amino-alcohol ligands for asymmetric alkynylation of aldehydes

Conformationally restricted amino alcohols based on carbohydrate scaffolds provide flexible and fine-tuneable libraries that greatly expand the range of ligands available in the Zn(OTf)2-mediated addition of alkynes to aldehydes, in some cases with very high stereoselectivities.

Studies on Pd(II)-catalyzed synthesis of (Z)-α-haloalkylidene-β- lactones from cyclocarbonylation of 2-alkynols and the subsequent coupling reactions

(Chemical Equation Presented) A good regio- and stereoselectivity was observed for the PdCl2-catalyzed cyclocarbonylation of 2-alkynols with CuCl2 affording (Z)-α-chloroalkylidene-β-lactones. The highly optically active (Z)-α-chloroa

Catalytic asymmetric addition of terminal alkynes to aldehydes mediated by (1R,2R)-2-(dimethylamino)-1,2-diphenylethanol

Catalytic asymmetric alkynylation of aldehydes with terminal alkynes was catalyzed by zinc triflate and (1R,2R)-2-(dimethylamino)-1,2-diphenylethanol in toluene to give the corresponding alcohols with high enantiomeric excess up to 98% in good yields.

Zn(ODf)2: Preparation and application in asymmetric alkynylation of aldehydes

A new Lewis acid, Zn(ODf)2, was first prepared from commercially available 3,3,4,4-tetrafluoro[1,2]oxathietane 2,2-dioxide in four steps with 56% yields and also was applied to catalyze highly enantioselective alkynylation of aldehydes in the presence of ligand (1S,2S)-3-(tert-butyldimethylsilyloxyl)-2-N,N-dimethylamino-1-(p- nitrophenyl)-propane-1-ol or ligand (-)-N-methylephedrine to afford the corresponding propargylic alcohols in high yields with up to 99% ee.