1440775-40-5Relevant academic research and scientific papers
A Catalyst Designed for the Enantioselective Construction of Methyl- and Alkyl-Substituted Tertiary Stereocenters
Claraz, Aurlie,Sahoo, Gokarneswar,Berta, Dnes,Madarsz, dm,Ppai, Imre,Pihko, Petri M.
, p. 669 - 673 (2016/02/27)
Tertiary methyl-substituted stereocenters are present in numerous biologically active natural products. Reported herein is a catalytic enantioselective method for accessing these chiral building blocks using the Mukaiyama-Michael reaction between silyl ketene thioacetals and acrolein. To enable remote enantioface control on the nucleophile, a new iminium catalyst, optimized by three-parameter tuning and by identifying substituent effects on enantioselectivity, was designed. The catalytic process allows rapid access to chiral thioesters, amides, aldehydes, and ketones bearing an α-methyl stereocenter with excellent enantioselectivities, and allowed rapid access to the C4-C13 segment of (-)-bistramide A. DFT calculations rationalized the observed sense and level of enantioselectivity.
A new class of non-C2-symmetric ligands for oxidative and redox-neutral palladium-catalyzed asymmetric allylic alkylations of 1,3-diketones
Trost, Barry M.,Donckele, Etienne J.,Thaisrivongs, David A.,Osipov, Maksim,Masters, James T.
, p. 2776 - 2784 (2015/03/04)
We report the discovery, synthesis, and application of a new class of non-C2-symmetric phosphoramidite ligands derived from pyroglutamic acid for use in both oxidative and redox-neutral palladium-catalyzed asymmetric allylic alkylations of 1,3-diketones. The resulting chiral products are typically obtained in high yield with good to excellent levels of enantioselectivity.
