Iron(iii)–salan complexes catalysed highly enantioselective fluorination and hydroxylation of β-keto esters and N-Boc oxindoles
作者:Xin Gu、Yan Zhang、Zhen-Jiang Xu、Chi-Ming Che
DOI:10.1039/c4cc01631a
日期:——
Chiral iron(III)âsalan complexes catalysed highly enantioselective α-fluorination and α-hydroxylation of β-keto esters and N-Boc oxindoles to give the corresponding products in high yields and good-to-excellent ee values under mild reaction conditions.
Bioinspired Divergent Oxidative Cyclization from Strictosidine and Vincoside Derivatives: Second‐Generation Total Synthesis of (−)‐Cymoside and Access to an Original Hexacyclic‐Fused Furo[3,2‐
<i>b</i>
]indoline
作者:Yingchao Dou、Cyrille Kouklovsky、Guillaume Vincent
DOI:10.1002/chem.202003758
日期:2020.12.18
The second‐generation synthesis of (−)‐cymoside as well as the formation of a new hexacyclic‐fused furo[3,2‐b]indoline framework is reported. After a Pictet–Spengler condensation between secologanin tetraacetate and tryptamine, the course of the cyclization of the 7‐hydroxyindolenine intermediate, generated by oxidation with an oxaziridine, depended on the stereochemistry of the 3‐position. The 3‐(S)‐strictosidine
据报道,(-)-cymoside的第二代合成以及新的六环融合呋喃[3,2- b ]二氢吲哚骨架的形成。仲硫代己宁四乙酸盐与色胺之间发生Pictet-Spengler缩合反应后,由恶唑烷氧化产生的7-羟基吲哚中间体中间环化的过程取决于3-位的立体化学。的3 - (小号)-strictosidine立体化学通过与C16-C17烯醇醚分子内偶合有效地传送cymoside的支架,而3 - ([R )立体化学-vincoside朝向与C18-C19末端烯烃并形成反应意外的笼状化合物。
Enantioselective N-heterocyclic carbene catalyzed formal [3+2] cycloaddition using α-aroyloxyaldehydes and oxaziridines
作者:Ryan W.F. Kerr、Mark D. Greenhalgh、Alexandra M.Z. Slawin、Polly L. Arnold、Andrew D. Smith
DOI:10.1016/j.tetasy.2016.10.012
日期:2017.1
An enantioselective N-heterocyclic carbene catalysed formal [3+2] cycloaddition has been developed for the synthesis of oxazolindin-4-one products. The reaction of oxaziridines and alpha-aroyloxyaldehydes under N-heterocyclic carbene catalysis provides the formal cycloaddition products with excellent control of the diastereo- and enantioselectivity (12 examples, up to >95:5 dr, >99:1 er). A matched-mismatched effect between the enantiomer of the catalyst and oxaziridine was identified, and preliminary mechanistic studies have allowed the proposal of a model to explain these observations. (C) 2016 Published by Elsevier Ltd.
DAVIS F. A.; BILLMERS J. M.; GOSCINIAK D. J.; TOWSON J. C.; BACH R. D., J. ORG. CHEM., 51,(1986) N 22, 4240-4245
作者:DAVIS F. A.、 BILLMERS J. M.、 GOSCINIAK D. J.、 TOWSON J. C.、 BACH R. D.
DOI:——
日期:——
Chemistry of oxaziridines. 13. Synthesis, reactions, and properties of 3-substituted 1,2-benzisothiazole 1,1-dioxide oxides
作者:Franklin A. Davis、James C. Towson、Dhiru B. Vashi、R. ThimmaReddy、John P. McCauley、Mark E. Harakal、Donald J. Gosciniak