Organocatalyzed Tsuji–Trost reaction: a new method for the closure of five- and six-membered rings
作者:Bojan Vulovic、Filip Bihelovic、Radomir Matovic、Radomir N. Saicic
DOI:10.1016/j.tet.2009.10.006
日期:2009.12
A combination of organotransition metal catalysis and organocatalysis allows for Tsuji–Trost 5-exo- and 6-exo-cyclizations of aldehydes. This transformation can also be accomplished as a catalytic asymmetric reaction, which affords vinylcyclopentane derivatives with up to 98%ee.
Role of Ring <i>Ortho</i> Substituents on the Configuration of Carotenoid Polyene Chains
作者:Minsoo Kim、Hyunuk Jung、Albert C. Aragonès、Ismael Díez-Pérez、Kwang-Hyun Ahn、Wook-Jin Chung、Dahye Kim、Sangho Koo
DOI:10.1021/acs.orglett.7b03930
日期:2018.1.19
The 9-(Z)-configuration was exclusively obtained in the carotenoid polyenechain irrespective of olefination and disconnection methods for terminal ortho-unsubstituted benzene rings. The 2,6-dimethyl substituents in the terminal rings secure an all-(E)-polyene structure. The single molecular conductance of the pure 9-(Z)-carotene was measured for the first time to be 1.53 × 10–4 ± 6.37 × 10–5G0, whose
9-(Z)-构型仅在类胡萝卜素多烯链中获得,而与末端邻-未取代的苯环的烯烃化和断开方法无关。末端环中的2,6-二甲基取代基可确保全(E)-多烯结构。首次测得纯9-(Z)-胡萝卜素的单分子电导为1.53×10 –4 ±6.37×10 –5 G 0,其值为全(E)-的47%胡萝卜素((3.23×10 -4)±(1.23×10 -4)G 0)。
Formal total synthesis of (−)-kainic acid
作者:HongWei Shi、JianLong Li、YueMeng Liu、ZuoLing Du、ZhiYan Huang、Na Zhao、Nan Li、Jun Yang
DOI:10.1016/j.tet.2016.07.040
日期:2016.9
This article reported an eight steps formal totalsynthesis of (−)-kainic acid in 16% overall yield from an enantiopure starting material. The key transformations include an efficient tandem N-allylation/SN2′ reaction to construct the 2,3-trans-3,4-cis tri-substituted pyrrolidine and a HgCl2-promoted methanolysis of 1,4-benzodithia-fulvene to furnish the ester group.
本文报道了从对映体纯原料以16%的总收率完成(-)-海藻酸的八步正式全合成。密钥变换包括一种有效串联的N-烯丙基化/ S Ñ 2'反应以构建2,3-反式-3,4-顺三取代的吡咯烷和氯化汞2 1,4- benzodithia-富烯的促进的以甲醇分解提供酯基。
[reaction: see text] A new chemo-, regio-, and stereoselective cascade reactionfeatures a novel isoxazole --> benzisoxazole rearrangement and affords highly functionalized, differentially protected compounds. The products of this reaction are directly converted to a number of complex, structurally diverse polycyclic molecules. These transformations highlight the unique chemistry inherent to readily