A Short and General Approach to the Synthesis of Styryllactones:(+)-Goniodiol, its Acetates and β-Trifluoromethyl Derivative, (+)-7-epi-Goniodiol and (+)-9-Deoxygoniopypyrone
Enantio- and Diastereoselective Synthesis of (E)-1,5-syn-Diols: Application to the Synthesis of the C(23)−C(40) Fragment of Tetrafibricin
摘要:
A highly stereoselective synthesis of (E)-1,5-syn-diols 6 Is described. The kinetically controlled hydroboration of allenyltrifluoroborate 8 with Soderquist borane 2 provides the (Z)-allylic trifluoroborate 9, which undergoes sequential allylboration with two different aldehydes to provide (E)-1,5-syn-diols 6 In 72-98% yields with > 95% ee and > 20:1 dr. Application of this method to the synthesis of the tetraflbricin C(23)-C(40) fragment 19 is described.
3,3′-Bithiophene-Based Chiral Bisphosphine Oxides as Organocatalysts in Silicon-Derived Lewis Acid Mediated Reactions
作者:Sergio Rossi、Tiziana Benincori、Laura Maria Raimondi、Maurizio Benaglia
DOI:10.1055/s-0039-1690777
日期:2020.4
This account summarizes the development of new biheteroaromatic chiral bisphosphine oxides. 3,3′-Bithiophene-based phosphine oxides (BITIOPOs) have been successfully used as organocatalysts to promote Lewis base catalyzed, Lewis acid mediated stereoselective transformations. These highly electron-rich compounds, in combination with trichorosilyl derivatives (allyltrichlorosilane and silicon tetrachloride)
Enantioselective <i>syn</i>- and <i>anti</i>-Alkoxyallylation of Aldehydes via Brønsted Acid Catalysis
作者:Shang Gao、Ming Chen
DOI:10.1021/acs.orglett.8b02653
日期:2018.10.5
A diastereo- and enantioselective alkoxyallylation via phosphoric acidcatalysis was reported. Under the developed conditions, either 1,2-syn- or 1,2-anti-alkoxyallylation adducts were obtained in good yields with high enantioselectivities.
A simple route to enantiomerically enriched oxazolidin-2-ones
作者:Daqiang Xu、K.Barry Sharpless
DOI:10.1016/s0040-4039(00)77462-4
日期:1993.2
The reaction of ene diols, which are readily available through catalytic asymmetric dihydroxylation of conjugated dienes, with p-tosylisocynate catalyzed by Pd(0) gave enantiomericallyenriched oxazolidin-2-ones in high yields.
Asymmetric Synthesis of Trisubstituted Vicinal Diols through Copper(I)‐Catalyzed Diastereoselective and Enantioselective Allylation of Ketones with Siloxypropadienes
trisubstituted vicinaldiols is accomplished by copper(I)-catalyzed diastereoselective and enantioselective reductive allylation of ketones with siloxypropadienes. The generation of both syn-diols and anti-diols is rationalized by DFT calculations, which show that cis-γ-siloxy-allyl copper species are generated favorably in the reduction of either 1-TBSO-propadiene or 1-TIPSO-propadiene by copper hydride
Development of a double allylboration reagent targeting 1,5-syn-(E)-diols: application to the synthesis of the C(23)–C(40) fragment of tetrafibricin
作者:Philippe Nuhant、Jeremy Kister、Ricardo Lira、Achim Sorg、William R. Roush
DOI:10.1016/j.tet.2011.06.008
日期:2011.9
Interest in the synthesis of the C(23) C(40) fragment 2 of tetrafibricin prompted us to develop a new method for the synthesis of 1,5-syn-(E)-diols. Toward this end, the kinetically controlled hydroboration of allenes 6, 33, ent-39, 42, and 45 with the Soderquist borane 25R were studied. Tetrabutylammonium allenyltrifluoroborate 45 gave superior results and was utilized in a double allylboration sequence with two different aldehydes to provide the targeted 1,5-syn-(E)-diols in generally high yields (72-98%), and with high enantioselectivity (>95% ee), diastereoselectivity (dr >20:1), and (E)/(Z) selectivity (>20:1). This new method was applied to the synthesis of the C(23) C(40) fragment 2 of tetrafibricin. (C) 2011 Elsevier Ltd. All rights reserved.