477199-83-0Relevant academic research and scientific papers
Asymmetric Total Syntheses of Di- and Sesquiterpenoids by Catalytic C?C Activation of Cyclopentanones
Dong, Guangbin,Hou, Si-Hua,Prichina, Adriana Y.,Zhang, Mengxi
, p. 7848 - 7856 (2020/03/24)
To show the synthetic utility of the catalytic C?C activation of less strained substrates, described here are the collective and concise syntheses of the natural products (?)-microthecaline A, (?)-leubehanol, (+)-pseudopteroxazole, (+)-seco-pseudopteroxazole, pseudopterosin A–F and G—J aglycones, and (+)-heritonin. The key step in these syntheses involve a Rh-catalyzed C?C/C?H activation cascade of 3-arylcyclopentanones, which provides a rapid and enantioselective route to access the polysubstituted tetrahydronaphthalene cores presented in these natural products. Other important features include 1) the direct C?H amination of the tetralone substrate in the synthesis of (?)-microthecaline A, 2) the use of phosphoric acid to enhance efficiency and regioselectivity for problematic cyclopentanone substrates in the C?C activation reactions, and 3) the direct conversion of serrulatane into amphilectane diterpenes by an allylic cyclodehydrogenation coupling.
Method for synthesizing alkyne through catalytic asymmetric cross coupling (by machine translation)
-
Paragraph 1084; 1104-1107; 1108; 1125-1126, (2020/01/12)
The invention belongs to the field of, asymmetric synthesis, and discloses a method for catalyzing asymmetric cross- coupling to synthesize: an alkyne, and the L method comprises, the following steps, of A: preparing B a cuprous, salt and C a: ligand; preparing a catalyst; adding a base; reacting the compound with the compound with the compound; and reacting the compound with the compound. Of these, one of them, X is selected from the group consisting of, R halogens. 1 Optionally substituted heteroarylsulfonylcyanamide groups selected from the, group consisting, of optionally substituted, phenyl groups In-flight vehicle, R6 Trialkyl silyl groups or alkyl radicals, R2 Cycloalkyl radicals optionally substituted with an, optionally substituted alkyl, (CH radical2 )n R4 Multi,layer chain, n=0-10,R saw blade4 A group selected, from, the group consisting of phenyl, alkenyl, aralkynyls, noonyloxy,and, noonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylphenyl disiloxy-radicals. R3 A ligand, selected from hydrogen or any of the functional groups, is selected from the group consisting of, hydrogen and any L other functional group. The method, R disclosed by the, A invention has the, advantages of good catalytic, R ’ effect, wide application range. and high catalytic efficiency, and the, method disclosed by the, invention has the. advantages of good catalytic effect, wide application range and high catalytic efficiency. (by machine translation)
Chemoenzymatic collective synthesis of optically active hydroxyl(methyl)tetrahydronaphthalene-based bioactive terpenoids
Batwal, Ramesh U.,Argade, Narshinha P.
, p. 11331 - 11340 (2015/11/27)
Starting from succinic anhydride and 2-methylanisole, a chemoenzymatic collective formal/total synthesis of several optically active tetrahydronaphthalene based bioactive natural products has been presented via advanced level common precursors; the natural product and antipode (-)/(+)-aristelegone B. Regioselective benzylic oxidations, stereoselective introduction of hydroxyl groups at the α-position of ketone moiety in syn-orientation, efficient enzymatic resolutions with high enantiomeric purity, stereoselective reductions, samarium iodide induced deoxygenations and tandem acylation-Wittig reactions without racemization and/or eliminative aromatization were the key features. An attempted diastereoselective synthesis of (±)-vallapin has also been described.
Cu(II)-catalyzed acylation by thiol esters under neutral conditions: Tandem acylation-wittig reaction leading to a one-pot synthesis of butenolides
Matsuo, Kazumasa,Shindo, Mitsuru
supporting information; experimental part, p. 5346 - 5349 (2011/01/05)
The first catalytic acylation of alcohols with a thiol ester present in Wittig reagents under neutral conditions catalyzed by the Cu(II) salt through a push-pull mechanism is reported. Furthermore, a new methodology for the one-pot lactonization of acyloins by a copper catalyst is developed. The synthetic utility of this method for the synthesis of natural products is shown.
Use of extracts from aristolochia in the treatment of AIDS
-
, (2008/06/13)
This invention relates to the use of extracts and compounds derived from the plant Aristolochia taliscana and their analogues in the treatment of AIDS.
