Synthesis of a tetrasubstituted arylphosphonate via the anionic phospho-Fries rearrangement

The anionic phospho-Fries rearrangement of phosphoric acid (3,5-di-isopropoxy)phenyl ester diethyl ester (11) gave rise to (2-hydroxy-4,6-di-isopropoxy-phenyl)phosphonic acid diethyl ester (12) in excellent yield. The phenol functionality of 12 was converted to the corresponding triflate which was coupled with vinyltributylstannane, under Stille conditions, to give a styrene. This molecule is intended to serve as the aromatic fragment in the synthesis of a phosphorus-based transition-state analogue for the hydrolysis of the S-(−)-zearalenone lactone.     

Synthesis of the new ring system 2-oxo-[1,4]oxazino[3,2-e]indole, heteroanalogue of Angelicin

A convenient synthesis of the 2-oxo-[1,4]oxazino[3,2-e]indole ring system, an heteroanalogue of Angelicin, is reported. Our synthetic approach consisted of the annelation of the oxazine ring on the indole moiety using 4-amino-5-hydroxy indoles as building blocks. The antiproliferative activity of the new compounds either in the dark or under UVA irradiation was investigated.     

新型异戊烯并环黄酮化合物的合成

以间苯三酚和3,3-二甲基烯丙酸为起始原料,通过苄基保护、甲基化、脱保护基、Clemmenson还原、乙酰化、Fries重排、Baker-Venkataraman重排和成环等10步反应, 以18.2%的总收率合成了1个新型异戊烯并环黄酮化合物BE-1C,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI-TOF)表征。     

An Efficient and Mild Preparation of Vinyl Diazo Carbonyl Compounds

The combination of (CF3CO)2O/Et3N is found to be a mild and efficient dehydration condition for β-hydroxy-α-diazo compounds.     

Facile Total Synthesis of Xanthotoxol

Xanthotoxol, a biologically active linear furocoumarin, has been efficiently synthesized from 7‐hydroxycoumarin in six steps. The key steps included two efficient rearrangements—Fries rearrangement and Claisen rearrangement—and a Baeyer–Villiger oxidation process. The overall yield of xanthotoxol was 29%. This approach also provided a new strategy to furnish easily furocoumarins with a hydroxyl group in the framework.     

浅谈Fries重排反应在有机合成中的应用

讨论了Fries重排反应的机理以及酚酯的结构、催化剂的选择及反应温度对反应的影响,并介绍了此重排在有机合成中的应用。     

A new pathway via intermediate 4-amino-3-fluorophenol for the synthesis of regorafenib

A practical synthetic route to regorafenib, in which the target compound was obtained via a 10-step synthesis starting from 2-picolinic acid, 4-chloro-3-(trifluoromethyl)aniline, and 3-fluorophenol, is reported. Crucial to the strategy is the preparation of 4-amino-3-fluorophenol via Fries and Beckman rearrangements using an economical and practical protocol. The main advantages of the route include inexpensive starting materials and an acceptable overall yield. A scale-up experiment was carried out to provide regorafenib with 99.96% purity in 46.5% total yield.     

An Efficient and Mild Deprotection of 1,3-Oxathiolanes to Carbonyl Compounds Using the Superoxide Ion

An efficient deprotection of 1,3-oxathiolanes to carbonyl compounds has been achieved under the mild reaction conditions of tetraethylammonium superoxide in an aprotic medium at room temperature.     

Mild and Efficient Method for Oxathioacetalization of Carbonyl Compounds

An efficient procedure for the protection of carbonyl compounds into the corresponding 1,3‐oxathioacetal has been achieved using PAS as catalyst.     

An Efficient Catalyst System at Mild Reaction Conditions Containing Rare Earth Metal Complexes

An efficient rare earth metal complex‐catalyzed cycloaddition reaction of CO₂ with propylene oxide using Hdpza (di(2‐pyrazyl)amine) as a N‐donor ligand has been accomplished in good to excellent yields with high selectivity. The effects of different rare earth metal salts, ligands and reaction conditions were examined. Catalytic reaction tests demonstrated that the incorporation of ErCl₃ and Hdpza can significantly enhance the catalytic reactivity of the TBAB (nBu₄NBr, tetra‐n‐butyl ammonium bromide) towards cycloaddition reaction of CO₂ and propylene oxide that produce cyclic carbonates under mild conditions without any co‐solvent.     

An Efficient Stereocontrolled Synthesis of Di-and Triunsaturated Carbonyl Compounds

ω-chlorodienals, ω-chlorodienones and 1,6-diacyl-1,3,5-hexatrienes were easily obtained from (E)-and (Z)-dichloroethylenes.     

New Mild and Efficient Synthesis of Peptidosulfonamides

This article describes a new route to peptidosulfonamide. Our study shows how sulfinamides were first obtained via nucleophilic cleavage of 3,6‐dihydrothiazine‐1‐oxide system and how the products can be subjected to oxidation with m‐chloroperbenzoic acid to give sulfonamides in good yield.     

Montmorillonite KSF,a Mild and Efficient Catalyst for Benzodithiepination of Carbonyl Compounds

A mild and efficient procedure for the protection of carbonyl compounds as 1,5-dihydro-3H-2,4-benzodithiepines in high yields is described by using a readily available and inexpensive KSF clay catalyst.     

An Efficient Synthesis of Pyrethroid Insecticides Containing Spiro-fused Cyclopropane Carboxylate

Among the active pyrethroid insecticides containing various substituted cyclpropanecarboxylates, esters derived from 2,2-dimethyl-5,6-benzospiro [2,4] heptene-1-carboxylic acid (1) have been 1 found to have particularly high activity, Our continuing interest in the synthesis of novel pyrethroid insecticides2 led us to a study of synthetic methodology for constructing spiro-fused systems such as (1).     

A Convenient One-Pot Completely Stereoselective Synthesis of trans-4-Hydroxystilbenes and Its Derivatives and X-Ray Structure of Its Precursor

Abstract

The synthesis of E-isomer of 4-Hydroxystilbene and its derivatives 3 by reductive elimination of the carbonyl function in 2-phenyl-1-(4-hydroxyphenyl)ethan-1-one and its derivatives 2 and the X-ray structure of 2a are described.     

对甲苯烷酰胺基三苯基季膦盐的合成

以对甲苯胺为原料,氯烷酰氯为连接基团合成了4个含酰胺键的季膦盐,其结构经1H NMR,13C NMR,31P NMR,IR和MS表征。     

含硅有机锗化合物的合成

报道了一类含硅有机锗化合物的合成。从Ｍｅ３ＳｉＣｌ，ＲＸ，ＧｅＯ２出发，经过氯化、格氏反应、亲核取代等反应，制得目标化合物－－二〔烃基二甲硅基甲基〕锗的二氯化物。它们的结构经元素分析和红外表征。     

1-苄基-2-(2-氯代烯丙基)-3-哌啶酮的简便合成

以苄基哌啶酮为原料,采用2,3-二氯丙烯与NaI原位生成烯丙基碘代物的方法,通过Stevens重排反应高效合成了天然生物碱常山碱的重要中间体——1-苄基-2-(2-氯代烯丙基)-3-哌啶酮,其结构经1H NMR,13C NMR,IR和HR-ESI-MS确证。