Total Synthesis and Evaluation of a Key Series of C5-Substituted Vinblastine Derivatives
摘要:
A remarkably concise seven- to eight-step total synthesis of a systematic series of key vinblastine derivatives is detailed and used to characterize the importance and probe the role of the C5 ethyl substituent (R = H, Me, Pr, CH=CH(2), C CH, CH(2)OH, and CHO vs Et). The analogues, which bear deep-seated structural changes accessible only by total synthesis, were prepared using a powerful intramolecular [4 + 2]/[3 + 2] cycloaddition cascade of 1,3,4-oxadiazoles ideally suited for use in the assemblage of the vindoline-derived lower subunit followed by their incorporation into the vinblastine analogues through the use of a single-step biomimetic coupling with catharanthine. The evaluation of the series revealed that the tubulin binding site surrounding this C5 substituent is exquisitely sensitive to the presence (Et > H, 10-fold), size (Me <= Et > Pr, 10-fold), shape (Et > CH=CH(2) and C CH, >4-fold), and polarity (Et > CHO > CH(2)OH, >10-20-fold) of this substituent and that on selected occasions only a C5 methyl group may provide analogues that approach the activity observed with the naturally occurring C5 ethyl group.
Hydroacylation of α,β-unsaturated esters via aerobic C–H activation
作者:Vijay Chudasama、Richard J. Fitzmaurice、Stephen Caddick
DOI:10.1038/nchem.685
日期:2010.7
using selectiveC–Hactivation as a direct route for generating reactive intermediates. In this article, we describe the use of aldehyde auto-oxidation as a simple, clean and effective method for C–Hactivation, resulting in the generation of an acyl radical. This acyl radical can be used for carbon–carbon bond formation and herein we describe the application of this method for the hydroacylation of α
[EN] ALICYCLIC MUSK FRAGRANCE COMPOUNDS<br/>[FR] COMPOSÉS ALICYCLIQUES DE PARFUM MUSQUÉ
申请人:SYMRISE AG
公开号:WO2020125993A1
公开(公告)日:2020-06-25
The present invention primarily relates to the use of a compound according to the general formula (I) wherein i) m is 1, n is 1, o is 0 or 1, Y is Hydrogen, or ii) m is 2, n is 0, o is 1, Y is methyl, and wherein X is O or methylene, R and R1 are each methyl or form together with the carbon atom attached to a carbonyl group, and R2 is methyl, ethyl, propyl, butyl, butan-2-one-4-yl, tetrahydrofuran-2-yl, or tetrahydrofuran-3-yl, as perfuming ingredients. Moreover, the present invention relates to perfume compositions and perfumed products comprising the before mentioned perfuming ingredients. Still more particularly, the invention relates to a method for producing said perfumed products and a method of imparting and/or increasing musk odor characteristics to perfumed products. This invention also relates to a process for the preparation of said compounds according to the general formula (I).
Efficient C(sp<sup>3</sup>)−H Carbonylation of Light and Heavy Hydrocarbons with Carbon Monoxide via Hydrogen Atom Transfer Photocatalysis in Flow**
作者:Fabian Raymenants、Tom M. Masson、Jesús Sanjosé‐Orduna、Timothy Noël
DOI:10.1002/anie.202308563
日期:2023.9.4
an efficient C−H functionalization process, enabling the regioselective installation of carbonyls in light and heavy hydrocarbons by using inexpensive carbon monoxide. Safe processing of hazardous CO and flammable alkanes is ensured in flow, with high gas-liquid mass transfer rates and fast reaction kinetics. Our method demonstrates the valorization of gaseous reagents, coupling light alkanes, CO, and
我们报告了一种高效的 C−H 官能化过程,通过使用廉价的一氧化碳,能够在轻质和重质烃中选择性安装羰基。具有高气液传质速率和快速反应动力学,可确保危险的 CO 和易燃烷烃的安全加工。我们的方法演示了气态试剂的增值,将轻质烷烃、CO 和烯烃偶联作为末端自由基陷阱。
A convenient route to chiral γ-lactones via asymmetric hydrogenation of γ-ketoesters using the RuCl3–BINAP–HCl catalytic system
作者:Eugenia V. Starodubtseva、Olga V. Turova、Maxim G. Vinogradov、Lilia S. Gorshkova、Vladimir A. Ferapontov、Marina I. Struchkova
DOI:10.1016/j.tet.2008.10.012
日期:2008.12
A convenient one-step synthesis of chiral gamma-lactones has been performed. The method is based on enantioselective hydrogenation of gamma-ketoesters using the RuCl3-BINAP-HCl catalytic system. Chiral gamma-lactones (91-99% ee) have been isolated in 57-88% yield. (C) 2008 Elsevier Ltd. All rights reserved.
Bouveault; Bongert, Bulletin de la Societe Chimique de France, 1902, vol. <3> 27, p. 1083,1088, 1089