Samarium(II)-Promoted Radical Spirocyclization onto an Aromatic Ring
摘要:
Samarium(II)-mediated spirocyclization onto an aromatic ring was achieved by the reaction of methyl 4-(4-oxoalkyl)benzoates with SmI2 in the presence of i-PrOH and HMPA, yielding methyl 1-alkyl-1-hydroxyspiro[4.5]dec-6-ene-8-carboxylates in moderate to high yields. Utilizing this chemistry, spiro[3.5] and -[5.5] systems, and sterically congested spiro[4.5] systems, were easily synthesized. For the successful conversion, appropriate activation of the aromatic ring has proven to be extremely important: while an ester or amide functionality on the aromatic ring can promote the spirocyclization, a sulfonamide substituent causes ortho cyclization.
[EN] A PROCESS FOR PREPARING INTERMEDIATES OF 10-PROPARGYL-10-DEAZAAMINOPTERIN (PRALATREXATE) SYNTHESIS AND THE INTERMEDIATES THEREOF<br/>[FR] PROCÉDÉ POUR LA PRÉPARATION D'INTERMÉDIAIRES DE SYNTHÈSE DE 10-PROPARGYL-10-DÉAZAAMINOPTÉRINE (PRALATREXATE) ET SES INTERMÉDIAIRES
申请人:AVRA LAB PRIVATE LTD
公开号:WO2013164856A1
公开(公告)日:2013-11-07
A process for preparation of 4-(1-(2,4-diaminopteridin-6-yl)pent-4-yn-2-yl)benzoic acid and other key intermediates in synthesis of 10-propargyl-10-deazaaminopterin (Pralatrexate) and the intermediates thereof. The 10-propargyl-10-deazaaminopterin (Pralatrexate) is obtained by peptide formation and ester hydrolysis of the intermediate compound 4-(1-(2,4-diaminopteridin-6-yl)pent-4-yn-2-yl)benzoic acid by methods known in the art.
Iridium-Catalyzed Synthesis of Substituted Indanones from Aromatic Carboxylates and Unsaturated Ketones
作者:Guodong Zhang、Zhiyong Hu、Giulia Bertoli、Lukas J. Gooßen
DOI:10.1021/acscatal.9b02536
日期:2019.9.6
A catalytic annulation is presented that provides straightforward, modular synthetic access to 3-substituted indanones from benzoic acids and α,β-unsaturated ketones. It is catalyzed by a bimetallic Ir/In system and proceeds via hydroarylation followed by Claisen condensation and optional retro-Claisen deacylation. The annulation may be combined into a one-pot procedure with the synthesis of the unsaturated
Highly Diastereo- and Enantioselective Cross-Cascade Reactions of Different Enones
作者:Huicai Huang、Wenbin Wu、Kailong Zhu、Juan Hu、Jinxing Ye
DOI:10.1002/chem.201204520
日期:2013.3.18
Cascading ketones! The first highly efficient asymmetric cross‐cascade reaction of different α,β‐unsaturated ketones catalyzed by an easily prepared bulky primary amine salt has been developed. It affords the corresponding diverse products containing three to four contiguous stereocenters with excellent enantio‐ and diastereoselectivities (see scheme).
One-Pot Photomediated Giese Reaction/Friedel–Crafts Hydroxyalkylation/Oxidative Aromatization To Access Naphthalene Derivatives from Toluenes and Enones
γ-aryl ketones and naphthalenes, were conveniently synthesized from readily available toluenes and enones through the synergistic combination of photoredox and Lewis acid catalysis. The direct synthesis of γ-aryl ketones represents a rare example of Giese reactions between benzylic C(sp3)–H and enones that avoids the use of prefunctionalized metallic nucleophiles. Naphthalene derivatives were accessed
Catalytic Enantioselective C–C Bond-Forming Reactions of Deconjugated Butyrolactams: Michael Addition to α,β-Unsaturated Aldehydes and Ketones
作者:Soumya Jyoti Singha Roy、Santanu Mukherjee
DOI:10.1021/acs.joc.8b02051
日期:2018.10.5
deconjugated butyrolactams has been demonstrated for enantioselective Michaeladditions to α,β-unsaturated aldehydes and ketones. These reactions are catalyzed by diphenylprolinol silyl ether and trans-1,2-diaminocyclohexane-derived bifunctional primary aminothiourea, respectively, producing the Michael adducts with moderate diastereoselectivities and good to excellent enantioselectivities (up to 99:1 er). Unlike