Diastereo- and Enantioselective Pd(II)-Catalyzed Additions of 2-Alkylazaarenes to N-Boc Imines and Nitroalkenes
摘要:
A chiral Pd(II)-bis(oxazoline) complex was found to be highly effective in promoting the first direct diastereo- and enantioselective addition of alkylazaarenes to N-Boc aldimines and nitroalkenes under mild conditions. Deprotection of Boc-protected products proceeded readily to provide amines in high yields.
Novel bifunctional thiourea–ammonium salt catalysts derived from amino acids: application to highly enantio- and diastereoselective aza-Henry reaction
作者:Hong-Yu Wang、Zhuo Chai、Gang Zhao
DOI:10.1016/j.tet.2013.04.079
日期:2013.6
development of new efficient and easily accessible catalysts has been one of the focuses in asymmetric phase-transfer catalysis. In this paper, a novel class of chiral bifunctional thiourea–ammonium phase-transfercatalysts were synthesized from commercially available α-amino acids. The structural modularity of these catalysts permits facile tunings to achieve optimum results, which was demonstrated
Organocatalytic Asymmetric Mannich Reaction of 3-Hydroxyoxindoles/3-Aminooxindoles with in Situ Generated <i>N</i>-Boc-Protected Aldimines for the Synthesis of Vicinal Oxindole–Diamines/Amino Alcohols
A highly efficient asymmetricMannichreaction of 3-monosubstituted 3-aminooxindoles/3-hydroxyoxindoles with in situ generated N-Boc-protected aldimines catalyzed by the chiral bifunctional thiourea–tertiary amine catalyst has been developed. Under mild reaction conditions, a series of structurally diverse vicinal oxindole–diamines/amino alcohols were smoothly obtained in moderate to high yields (up
Asymmetric Disulfonimide-Catalyzed Synthesis of δ-Amino-β-Ketoester Derivatives by Vinylogous Mukaiyama-Mannich Reactions
作者:Qinggang Wang、Manuel van Gemmeren、Benjamin List
DOI:10.1002/anie.201407532
日期:2014.12.1
organocatalytic asymmetricsynthesis of δ‐amino‐β‐ketoester derivatives has been developed. A chiral disulfonimide (DSI) serves as a highly efficient precatalyst for a vinylogous Mukaiyama–Mannich reaction of readily available dioxinone‐derived silyloxydienes with N‐Boc‐protected imines, delivering products in excellent yields and enantioselectivities. The synthetic utility of this reaction is illustrated
One-Pot Synthesis of α-Amino Acids from CO<sub>2</sub> Using a Bismetal Reagent with Si–B Bond
作者:Tsuyoshi Mita、Jianyang Chen、Masumi Sugawara、Yoshihiro Sato
DOI:10.1021/ol302952r
日期:2012.12.21
TsOH·H2O, precursors of N-Boc-imines can be converted into the corresponding α-aryl or α-alkenyl glycine derivatives under gaseous CO2 in moderate-to-high yields with a single operation. α-Isobutenyl glycine thus obtained can be further derivatized into various types of α-aminoacids including N-Boc-leucine, serine, and glycine derivatives in short steps.