440369-03-9Relevant academic research and scientific papers
Stereocontrolled Synthesis of 1,4-Dicarbonyl Compounds by Photochemical Organocatalytic Acyl Radical Addition to Enals
Goti, Giulio,Bieszczad, Bartosz,Vega-Pe?aloza, Alberto,Melchiorre, Paolo
, p. 1213 - 1217 (2019/01/04)
We report a visible-light-mediated organocatalytic strategy for the enantioselective acyl radical conjugate addition to enals, leading to valuable 1,4-dicarbonyl compounds. The process capitalizes upon the excited-state reactivity of 4-acyl-1,4-dihydropyridines that, upon visible-light absorption, can trigger the generation of acyl radicals. By means of a chiral amine catalyst, iminium ion activation of enals ensures a stereoselective radical trap. We also demonstrate how the combination of this acylation process with a second catalyst-controlled bond-forming event allows to selectively access the full matrix of all possible stereoisomers of the resulting 2,3-substituted 1,4-dicarbonyl products.
Enantioselective rhodium-catalyzed allylic substitution with a nitrile anion:construction of acyclic quaternary carbon stereogenic centers
Turnbull, Ben W. H.,Evans, P. Andrew
, p. 6156 - 6159 (2015/06/02)
A direct and highly enantioselective rhodium-catalyzed allylic alkylation of allyl benzoate with α-substituted benzyl nitrile pronucleophiles is described. This simple protocol provides a new approach toward the synthesis of acyclic quaternary carbon stereogenic centers and provides the first example of the direct asymmetric alkylation of a nitrile anion. The synthetic utility of the nitrile products is amply demonstrated through conversion to various functional groups and the synthesis of a bioactive aryl piperazine in an expeditious four-step sequence.
Enantioselective construction of quaternary stereogenic centers from tertiary boronic esters: Methodology and applications
Sonawane, Ravindra P.,Jheengut, Vishal,Rabalakos, Constantinos,Larouche-Gauthier, Robin,Scott, Helen K.,Aggarwal, Varinder K.
, p. 3760 - 3763 (2011/06/22)
Pin it down: A range of substrates that bear versatile functional groups with quaternary stereogenic centers have been prepared with very high enantioselectivity from tertiary boronic esters (see scheme; Cb=N,N-diisopropylcarbamoyl, pin=pinacolato). The preparation of allylboronic esters bearing contiguous quaternary and tertiary stereogenic centers, and applications to natural product synthesis are also reported.
Asymmetric Construction of Quaternary Centers by Enantioselective Allylation: Application to the Synthesis of the Serotonin Antagonist LY426965
Denmark, Scott E.,Fu, Jiping
, p. 1951 - 1953 (2007/10/03)
(Matrix Presented) Catalytic enantioselective allylation with a chiral bisphosphoramide was applied to the synthesis of LY426965, a serotonin antagonist. The key step, addition of a 3,3-disubstituted allyltrichlorosilane to benzaldehyde, provided the addu
