874911-71-4Relevant academic research and scientific papers
A Straightforward Sequential Approach for the Enantioselective Synthesis of Optically Active α-Arylmethanol-1,2,3-Triazoles
Andrade, Floyd C. D.,Pugnal, Lucas V. B. L.,Betim, Hugo L. I.,Vani, Jéssica F.,Zukerman-Schpector, Julio,Schwab, Ricardo S.
, p. 5467 - 5476 (2018)
Herein we describe a compelling sequential methodology for obtaining optically active α-arylmethanols-1,2,3-triazoles. The approach is based on the enantioselective alkynylation of aldehydes followed by a one-pot two-step desilylation/CuI-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC), providing the corresponding products with excellent yields and high levels of enantioselectivity. Furthermore, the click chemistry can be performed without affecting the enantiomeric excess. The application of the reaction has been demonstrated in the synthesis of a 1,2,3-triazole analog of antihistaminic and anticholinergic drug (R)-orphenadrine.
Catalytic asymmetric enyne addition to aldehdyes and Rh(I)-catalyzed stereoselective domino Pauson-Khand/[4 + 2] cycloaddition
Chen, Wei,Tay, Jia-Hui,Ying, Jun,Yu, Xiao-Qi,Pu, Lin
, p. 2256 - 2265 (2013/04/24)
The 1,1′-bi-2-naphthol-ZnEt2-Ti(OiPr) 4-Cy2NH system is found to catalyze the 1,3-enyne addition to aliphatic aldehydes as well as other aldehydes at room temperature with 75-96% yield and 82-97% ee. This system is also broadly applicable for the highly enantioselective reaction of other alkyl-, aryl-, and silylalkynes with structurally diverse aldehydes. The propargylic alcohols prepared from the catalytic asymmetric enyne addition to aliphatic aldehydes are used to prepare a series of optically active trienynes. In the presence of a catalytic amount of [RhCl(CO)2]2 and 1 atm of CO, the optically active trienynes undergo highly stereoselective domino Pauson-Khand/[4 + 2] cycloaddition to generate optically active multicyclic products. The Rh(I) catalyst is also found to catalyze the coupling of a diyne with CO followed by [4 + 2] cycloaddition to generate an optically active multicyclic product. These transformations are potentially useful for the asymmetric synthesis of polyquinanes containing a quaternary chiral carbon center.
