A modular and divergent approach to spirocyclic pyrrolidines
作者:Benjamin D. A. Shennan、Peter W. Smith、Yusuke Ogura、Darren J. Dixon
DOI:10.1039/d0sc03676e
日期:——
An efficient three-step sequence to afford a valuable class of spirocyclic pyrrolidines is reported. A reductive cleavage/Horner–Wadsworth–Emmons cascade facilitates the spirocyclisation of a range of isoxazolines bearing a distal β-ketophosphonate. The spirocyclisation precursors are elaborated in a facile and modular fashion, via a [3 + 2]-cycloaddition followed by the condensation of a phosphonate
Nickel-catalyzed coupling of R<sub>2</sub>P(O)Me (R = aryl or alkoxy) with (hetero)arylmethyl alcohols
作者:Wei-Ze Li、Zhong-Xia Wang
DOI:10.1039/d1ob00086a
日期:——
α-Alkylation of methyldiarylphosphine oxides with (hetero)arylmethyl alcohols was performed under nickelcatalysis. Various arylmethyl and heteroarylmethyl alcohols can be used in this transformation. A series of methyldiarylphosphine oxides were alkylated with 30–90% yields. Functional groups on the aromaticrings of methyldiarylphosphine oxides or arylmethyl alcohols including OMe, NMe2, SMe, CF3, Cl, and
Herein is described the development of an intensified continuous flow process for the preparation of a library of alkyl phosphonates through a Michaelis–Arbuzovrearrangement. A careful process optimization and thorough analysis of the competitive reactions led to a very attractive protocol with unprecedented productivities (up to 4.97 kg of material per day) and a low environmental footprint with
本文描述了通过 Michaelis-Arbuzov 重排制备烷基膦酸酯库的强化连续流动工艺的发展。仔细的工艺优化和对竞争反应的彻底分析产生了一个非常有吸引力的方案,具有前所未有的生产力(每天高达 4.97 公斤的材料)和低环境足迹,没有溶剂、添加剂、催化剂和废物。方便地实施在线低场31 P NMR 监测,以实现快速优化和过程监测。还评估了两个关键的烷基膦酸中间体在连续流动条件下对P的 α-氨基膦酸衍生物的前所未有的二氮烯二羧酸介导的亲电胺化苯丙氨酸和丙氨酸,分别是天然氨基酸苯丙氨酸和丙氨酸的生物等排体。
7-Acylamino-3-substituted-3-cephem-4-carboxylic acids, processes for their preparation and pharmaceutical compositions containing them
申请人:SMITHKLINE BECKMAN CORPORATION
公开号:EP0000272A1
公开(公告)日:1979-01-10
Cephalosporins with the formula
in which R represents various acyl substituents;
n represents 24, preferably 2,
n' represents 1-4, preferably 1,
R' represents hydrogen or lower alkyl from one to four carbons, show antibacterial activity.
They can be prepared by reacting the corresponding 3-acetoxy- methyl cephalosporin with the appropriate carboxyalkylamino-alkyltetrazolethione. The tet- razolethiones used as intermediates also form part of the invention.
头孢菌素
其中 R 代表各种酰基取代基;
n 代表 24,最好是 2、
n' 代表 1-4,最好是 1、
R'代表氢或 1 至 4 个碳原子的低级烷基,具有抗菌活性。
它们可通过相应的 3-乙酰氧基甲基头孢菌素与适当的羧基烷基氨基烷基四唑硫酮反应制备。用作中间体的四唑硫酮也是本发明的一部分。
Palladium-Catalyzed Hydrophosphonylation of Alkenes with Dialkyl H-Phosphonates
作者:Mathieu Candy、Sophie A. L. Rousseaux、Alberto Cirugeda San Román、Monika Szymczyk、Pawel Kafarski、Eric Leclerc、Emmanuel Vrancken、Jean-Marc Campagne
DOI:10.1002/adsc.201400190
日期:2014.8.11
AbstractThe palladium‐catalyzed hydrophosphonylation of alkenes with previously unreactive acyclic dialkyl H‐phosphonates has been developed. A catalyst system based on palladium/DavePhos or palladium/SPhos enables the transformation of various alkenes to phosphonates in moderate to good yields and with excellent levels of regioselectivity. Hydrophosphonylations with internal, disubstituted and/or unactivated alkenes are also reported.magnified image