Short synthesis of noscapine, bicuculline, egenine, capnoidine, and corytensine alkaloids through the addition of 1-siloxy-isobenzofurans to imines
摘要:
A concise diastereotioselective strategy for the synthesis of noscapine, bicuculiine, and egenine (1a-c), as well as capnoidine and corytensine (2a,b), was developed using diastereoselective addition of 1-siloxy-isobenzofurans 4a and 4b to immium ion 5 in a one-pot approach. The synthesis features the use of imine 13 obtained through Bischler-Napieralsky reaction from airline 11. The addition of ionic liquids as addictives in the reactions afforded erythro configuration in major adduct compounds. The synthetic route can also be applied in the total synthesis of promising tubulin binding agent EM105 (3). (C) 2010 Elseviet Ltd. All rights reserved.
Effective Partial Alkynylation of Carboxylic Acid Derivatives to Alkynyl Ketones
作者:Sang-Jun Yim、Min-Hyeok Kim、Duk-Keun An
DOI:10.5012/bkcs.2010.31.02.286
日期:2010.2.20
The reaction of carboxylic acid derivatives such as esters, acid chlorides and acid anhydrides with alkynyl lithiums in the presence of lithium morpholinide and $BF_3\cdot}OEt_2$ gave alkynyl ketones in good yield (73-96%).
Bestimmung der ionenpaar-basizitǎt von lithium- und kaliumamiden
作者:Hubertus Ahlbrecht、Gunther Scheneider
DOI:10.1016/s0040-4020(01)82054-8
日期:1986.1
Ion pair basicities of lithio and potassio salts of some secondary amines were determined by equilibration with benzyl compounds. With these bases it is possible to span a range of about 19 pK-units from pK = 27 up to 46. The structural dependence of thermodynamic as well as kinetic basicity is discussed. Some new effective amide bases for preparative purposes are recommended. For the first time the
Regio- and Chemoselective Metalation of Chloropyrimidine Derivatives with TMPMgCl⋅LiCl and TMP<sub>2</sub>Zn⋅2 MgCl<sub>2</sub>⋅2 LiCl
作者:Marc Mosrin、Paul Knochel
DOI:10.1002/chem.200801831
日期:2009.1.26
Efficient zincation and magnesiation of chlorinated pyrimidines can be performed at convenient temperatures (e.g., 25 and 55 °C) by using TMPMgCl⋅LiCl and TMP2Zn⋅2 MgCl2⋅2 LiCl (TMP=2,2,6,6‐tetramethylpiperidyl) as effective bases. Quenching of the resulting zincated or magnesiated pyrimidines with various electrophiles furnishes highlyfunctionalized pyrimidines in 51–93 % yield. Oxidative aminations
Chemoselective Activation of Diethyl Phosphonates: Modular Synthesis of Biologically Relevant Phosphonylated Scaffolds
作者:Pauline Adler、Amandine Pons、Jing Li、Jörg Heider、Bogdan R. Brutiu、Nuno Maulide
DOI:10.1002/anie.201806343
日期:2018.10
Phosphonates have garnered considerable attention for years owing to both their singular biological properties and their synthetic potential. State‐of‐the‐art methods for the preparation of mixed phosphonates, phosphonamidates, phosphonothioates, and phosphinates rely on harsh and poorly selective reaction conditions. We report herein a mild method for the modular preparation of phosphonylated derivatives
A simple and efficient synthesis of isoquinoline and 3,4-dihydroisoquinoline derivatives is described. 1-Alkyl(or aryl)isoquinoline and 1-isoquinolinamine derivatives were obtained by intramolecula...