Stereoselective Modification of <i>N</i>-(α-Hydroxyacyl)-glycinesters via Palladium-Catalyzed Allylic Alkylation
作者:Alexander Horn、Uli Kazmaier
DOI:10.1021/acs.orglett.9b01497
日期:2019.6.21
excellent nucleophiles in Pd-catalyzed allylic alkylation. The method allows for the stereoselective introduction of a wide range of side chains, including highly functionalized ones. Both diastereomers can be accessed through variation of the reaction conditions. Furthermore, the use of stannylated carbonates introduces vinylstannane motifs, which are eligible for subsequent C–C coupling reactions.
Biosynthesis-Inspired Approach to Kujounin A<sub>2</sub> Using a Stereoselective Tsuji–Trost Alkylation
作者:Alexander Burtea、Scott D. Rychnovsky
DOI:10.1021/acs.orglett.8b02530
日期:2018.9.21
proposed for the kujounins A1 and A2 beginning from ascorbicacid, which in turn inspired a synthetic approach to kujounin A2. The ring system was assembled in two steps using a stereoselective Tsuji–Trost reaction followed by ozonolysis. The chemically labile disulfide was introduced in several more steps. These results will make kujounin and its analogues available for further evaluation.
从抗坏血酸开始,提出了一种新的kujounin A 1和A 2生物合成方法,这反过来又激发了一种合成kujounin A 2的方法。使用立体选择性的Tsuji-Trost反应,然后进行臭氧分解,将环系统分为两个步骤进行组装。化学不稳定的二硫键又经过几个步骤引入。这些结果将使苦瓜素及其类似物可用于进一步评估。
Chelated Enolates of Amino Acid Esters—Efficient Nucleophiles in Palladium-Catalyzed Allylic Substitutions
Complementary to the Claisen rearrangement, the title reaction-which when carried out with chelatedenolates of amino acid esters as nucleophiles gives rise to unsaturated amino acids-preferentially provides anti instead of syn products. This palladium-catalyzed reaction proceeds under very mild conditions and is suitable for the synthesis of enantiomerically pure amino acids (see reaction scheme)