38693-58-2Relevant academic research and scientific papers
Neighboring Carbonyl Group Assisted Oxyacetoxylation of Propargylic Carboxylates with Retention of Chirality under Metal Free Condition
Pradhan, Tapas R.,Mohapatra, Debendra K.
supporting information, p. 3605 - 3611 (2019/07/04)
A metal-free oxyacetoxylation method of primary, secondary and tertiary propargylic carboxylates with retention of chirality was presented. The reaction proceeds through the intramolecular nucleophilic attack of the neighboring carbonyl group on an alkynyliodonium intermediate. The process is general with broad substrate scope and is amenable for application to a variety of propargyl carboxylates including those obtained from natural products. Insight into the mechanistic pathway by isotopic labelling (using H2O18 and D2O) and controlled experiments confirmed. (Figure presented.).
Silver(I)-Catalyzed Addition of Phenols to Alkyne Cobalt Cluster Stabilized Carbocations
Valderas, Carolina,Casarrubios, Luis,Lledos, Agusti,Ortu?o, Manuel A.,de la Torre, María C.,Sierra, Miguel A.
supporting information, p. 9015 - 9023 (2016/07/06)
A smooth catalytic method to use phenols as the nucleophilic partner in the Nicholas reaction has been developed. The method uses either AgIor AuIcatalysts with AgClO4or AgBF4as the most efficient catalysts tested. Neither additional additives nor cocatalysts were required and the formation of the corresponding phenol adducts occurred in excellent yields. The process has the single limitation of the inability of less nucleophilic phenols (4-nitrophenol) to generate the corresponding adducts. Additionally, the reaction is highly diastereoselective. DFT calculations allow a catalytic cycle to be proposed that involves trimetallic intermediates; the rate-determining step of the reaction is hydroxy-group elimination in a cobalt–silver trimetallic intermediate.
Evidence for concerted processes in the course of the homoallenylic transposition
Aouf, Chahinez,Galy, Nicolas,Santelli, Maurice
supporting information, p. 3225 - 3233 (2013/04/24)
The hydrolysis of β-allenic tosylates produces mainly 2-methylenecyclobutanols resulting from a homoallenylic participation along with isomeric 2-methylenecyclobutanol minor products coming from a 1234-1243 rearrangement. Structures of various cyclopropylvinyl carbocations involved in the course of the hydrolysis have been determined by computational studies. For acyclic tosylates, the hydrolysis of one β-deuterated allenic tosylate confirmed the nucleophilic attack on the corresponding nonclassical carbonium ion before its evolution to a more stable cyclopropylvinyl carbocation. In the case of one cyclic β-allenic tosylate, the structure of the products has been checked by the use of deuterated isotopomer.
Highly enantioselective and regioselective copper-catalyzed 1,4 addition of grignard reagents to cyclic enynones
Tissot, Matthieu,Perez Hernandez, Alexandra,Mueller, Daniel,Mauduit, Marc,Alexakis, Alexandre
supporting information; experimental part, p. 1524 - 1527 (2011/05/04)
In this letter we describe an unusual result in terms of regioselectivity with respect to copper-catalyzed conjugate additions of various Grignard reagents to cyclic enynones. The use of Cu(OTf)2 and NHC ligand L1 as the catalyst combination in CH2Cl2 led to the unique formation of the 1,4 adduct. This selectivity does not follow the general trend previously observed in the literature using extended Michael acceptors. Moreover these reactions allowed for the creation of a quarternary stereogenic center with enantioselectivities up to 97% ee.
Stereoselective One-Pot synthesis of 1-Aminoindanes and 5,6-Fused azacycles using a Gold-Catalyzed Redox-Pinacol-Mannich-Michael cascade
Yeom, Hyun-Suk,Lee, Youngun,Jeong, Jaewon,So, Eunsoo,Hwang, Soojin,Lee, Ji-Eun,Lee, Shim Sung,Shin, Seunghoon
supporting information; experimental part, p. 1611 - 1614 (2010/06/15)
"Chemical Equation Presented" Just another Mannich Monday: A cascade intramolecular redox-pinacol-Mannich-Michael reaction sequence catalyzed by gold complexes can be used to generate a variety of structures including spirocycles, 1-aminoindanes, and 5,6-fused azabicycles that have a quaternary carbon center. The reaction is characterized by complete atom-economy, high diastereoselectivity, and remarkable efficiency through tandem reactions.
