Racemicazlactones are transformed into valuable chiral heterocycles via an asymmetric organocatalytic Mannich reaction followed by gold‐catalyzed cyclization or reduction.
A general method to synthesize functionalized allyl α-amino acid derivatives through an irreversible oxy-2-azonia-Cope rearrangement is reported. In the presence of AlCl3, the reaction of imino ethyl glyoxalates with various β,γ-unsaturated ketones furnished the corresponding allyl α-amino acid derivatives. The key to the success of this method is the amide bond formation, which makes the rearrangement
Synthesis of α-(3-Indolyl)glycine Derivatives via Spontaneous Friedel-Crafts Reaction between Indoles and Glyoxylate Imines
作者:Biao Jiang、Zuo-Gang Huang
DOI:10.1055/s-2005-869978
日期:——
Mannich-type Friedel-Crafts reaction between indoles and ethyl glyoxylate imines proceeded spontaneously in the absence of an acid catalyst. Ethyl alpha-(3-indolyl)glycinates were obtained in moderate to high yields. Reaction with (R)-alpha-methylbenzylamine derived imine afforded chiral alpha-(3-indolyl)glycinates with good diastereoselectivities (up to 96:4).
Visible-Light-Mediated, Chemo- and Stereoselective Radical Process for the Synthesis of <i>C</i>-Glycoamino Acids
作者:Peng Ji、Yueteng Zhang、Yongyi Wei、He Huang、Wenbo Hu、Patrick A. Mariano、Wei Wang
DOI:10.1021/acs.orglett.9b00724
日期:2019.5.3
for efficient synthesis of C-glycosyl amino acids is described. Different from typical photoredox-catalyzed reactions of imines, the new process follows a pathway in which α-imino esters serve as electrophiles in chemoselective addition reactions with nucleophilic glycosyl radicals. The process is highlighted by the mild nature of the reaction conditions, the highly stereoselectivity attending C–C
A Practical and Efficient Total Synthesis of Potent Insulinotropic (2S,3R,4S)-4-Hydroxyisoleucine through a Chiral N-Protected γ-Keto-α-aminoester
作者:Sandra De Lamo Marin、Cédric Catala、Sreekantha Ratna Kumar、Alain Valleix、Alain Wagner、Charles Mioskowski
DOI:10.1002/ejoc.201000378
日期:2010.7
(2S,3R,4S)-4-Hydroxyisoleucine, which exhibits remarkable insulinotropic activity, is expected to be a potent drug to treat type II diabetes. We propose herein a four-step synthesis of the enantiopure natural product on the basis of successive Mannich condensation, catalytic epimerization, N-para-methoxyphenyl deprotection, and diastereoselective reduction. This compact economical and scalable sequence
(2S,3R,4S)-4-羟基异亮氨酸具有显着的促胰岛素活性,有望成为治疗 II 型糖尿病的有效药物。我们在此提出基于连续曼尼希缩合、催化差向异构化、N-对甲氧基苯基脱保护和非对映选择性还原的四步合成对映纯天然产物。这种紧凑经济且可扩展的序列能够完美地控制三个连续的手性中心。它不涉及任何色谱纯化,在我们优化的条件下以 >99% de、>99% ee 和 22% 的总收率获得所需化合物。