1197983-12-2Relevant academic research and scientific papers
Chiral Phosphoric-Acid-Catalyzed Cascade Prins Cyclization
Sun, Huai-Ri,Zhao, Qingyang,Yang, Hui,Yang, Sen,Gou, Bo-Bo,Chen, Jie,Zhou, Ling
, p. 7143 - 7148 (2019/09/07)
Asymmetric Prins cyclization of in situ generated quinone methides and o-aminobenzaldehyde has been developed with chiral phosphoric acid as an efficient catalyst. This unconventional method provides a facile access to diverse functionalized trans-fused pyrano-/furo-tetrahydroquinoline derivatives in excellent yield and with excellent diastereo- and enantioselectivities (up to 99% yield and 99% ee). Mechanistic studies suggested that the three adjacent tertiary stereocenters were constructed through the sequential formation of C-O, C-C, and C-N bonds.
Palladium(II)-catalyzed enantio- and diastereoselective synthesis of pyrrolidine derivatives
Jana, Ranjan,Pathak, Tejas P.,Jensen, Katrina H.,Sigman, Matthew S.
, p. 4074 - 4077 (2012/09/22)
A palladium-catalyzed enantio- and diastereoselective synthesis of pyrrolidine derivatives is described. Initial intramolecular nucleopalladation of the tethered protected amine forms the pyrrolidine moiety and a quinone methide intermediate. A second nucleophile adds intermolecularly to afford diverse products in high enantio- and diastereoselectivity.
Synthesis and preliminary biological studies of 3-substituted indoles accessed by a palladium-catalyzed enantioselective alkene difunctionalization reaction
Pathak, Tejas P.,Gligorich, Keith M.,Welm, Bryan E.,Sigman, Matthew S.
supporting information; experimental part, p. 7870 - 7871 (2010/08/05)
A unique alkene difunctionalization reaction that allows rapid construction of molecular complexity around the biologically relevant indole framework has been developed. The reaction proceeds with up to 87% yield, 99:1 er, and >20:1 dr. Evaluation of several of the compounds revealed promising anticancer activity against MCF-7 cells.
Advancing the mechanistic understanding of an enantioselective palladium-catalyzed alkene difunctionalization reaction
Jensen, Katrina H.,Webb, Jonathan D.,Sigman, Matthew S.
supporting information; experimental part, p. 17471 - 17482 (2011/02/27)
The mechanism of an enantioselective palladium-catalyzed alkene difunctionalization reaction has been investigated. Kinetic analysis provides evidence of turnover-limiting attack of a proposed quinone methide intermediate with MeOH and suggests that copper is involved in productive product formation, not just catalyst turnover. Through examination of substrate electronic effects, a Jaffe relationship was observed correlating rate to electronic perturbation at two positions of the substrate. Ligand effects were evaluated to provide evidence of rapid ligand exchange between palladium and copper as well as a correlation between ligand electronic nature and enantioselectivity.
Palladium-catalyzed enantioselective addition of two distinct nucleophiles across alkenes capable of quinone methide formation
Jensen, Katrina H.,Pathak, Tejas P.,Zhang, Yang,Sigman, Matthew S.
supporting information; experimental part, p. 17074 - 17075 (2010/03/25)
(Chemical Equation Presented) A sequential intramolecular-intermolecular enantioselective alkene difunctionalization reaction has been developed which is thought to proceed through Pd-catalyzed quinone methide formation. The synthesis of new chiral heterocyclic compounds with adjacent chiral centers is achieved in enantiomeric ratios up to 99:1 and diastereomeric ratios up to 10:1.
