A New Synthesis of Polysubstituted Cyclopropanes

Polysubstituted cyclopropane derivatives (3a-3h) could be obtained by reaction of activate olefinic compounds (2) with the cyanophosphates (1) aldehydes (benzaldehyde, cinnamaldehyde and croton-aldehyde) in the presence of butyllithium and tetra-methylethylenediamine in tetrahydrofuran via a Michael addition followed by 1,3-elimination.     

Facile Synthesis of Polysubstituted Cyclopropanes in a Two-Phase Solid-Liquid System

The Michael addition of α-chloro esters to α,β-unsaturated systems was catalyzed by phase transfer catalyst, and the some polysubstituted cyclopropanes were facilly synthesized.     

Stereoselective Synthesis of Polysubstituted Cyclopropanes from Poly(ethylene glycol)Supported Pyridinium Ylide

Polysubstituted cyclopropanes were efficiently prepared with poly(ethylene glycol)(PEG) as soluble support. The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile(R=CN) or ethyl arylidenecyanoacetate(R=COOEt) in the presence of triethylamine(TEA) afforded PEG-supported cyclopropanecarboxylates, which were cleaved by 1% KCN/EtOH to obtain polysubstituted cyclopropanes with exclusive trans-selectivity and good yields.     

Synthesis of Polysubstituted Ferrocenesulfoxides

The purpose of the study is to design synthetic methodologies, especially directed deprotometalation using polar organometallic reagents, to access polysubstituted ferrocenesulfoxides. From enantiopure 2-substituted (SiMe₃, PPh₂) S-tert-butylferrocenesulfoxides, a third substituent was first introduced at the 5 position (SiMe₃, I, D, C(OH)Ph₂, Me, PPh₂, CH₂NMe₂, F) and removal of the trimethylsilyl group then afforded 2-substituted ferrocenesulfoxides unreachable otherwise. Attempts to apply the “halogen dance” reaction to the ferrocenesulfoxide series led to unexpected results although rationalized in light of calculated pK_a values. Further functionalizations were also possible. Thus, new enantiopure, planar chiral di- and trisubstituted ferrocenes have been obtained, in addition to several original 2-substituted, 2,3- and 2,5-disubstituted, 2,3,5-trisubstituted and even 2,3,4,5-tetrasubstituted ferrocenesulfoxides, also enantiopure.     

New One-Pot Synthesis of Polysubstituted Benzofurans and Benzo-1,4-dioxines

It has been revealed that the copper(II) triflate catalyzed reaction of ethyl-2-diazo-3-oxobutanoate with phenols followed by cyclization of the intermediate enol in the presence of polyphosphoric acid is a simple and efficient method of synthesis of polysubstituted benzofurans. The use of pyrocatechol leads to the corresponding substituted 1,4-benzodioxine-2-carboxylates as major products.     

Synthesis of Regioselectively Deuterated Cyclopropanes

A regioselective synthesis of deuterated aliphatic cyclopropanes has been developed to furnish labeled substrates for gas-phase ion-molecule reaction studies.     

A Facile Synthesis of Benzoxazolyl Cyclopropanes

2′-Benzoxazolyl substituted cyclopropane derivatives were synthesized in the yield of 73-89% from the reaction of telluronium ylides with chalcones.     

多取代吡咯基脂肪酸的合成

许多吡咯衍生物具有生理活性,近年来发现1-芳基取代吡咯具有明显的生理效应,作者曾合成了部分多取代吡咯化合物,并研究了其NMR谱。     

One-Pot Three-Component Synthesis of Polysubstituted Tetrahydroindoles

Chemistry of Heterocyclic Compounds - A series of novel fused pyrrole derivatives was synthesized by one-pot three-component reaction of β-enaminoketones, derived from cyclohexane-1,3-dione or...     

新型多取代3-烯基吲哚的合成

开发了一种以吲哚为起始原料,合成具有多个反应位点的多取代3-烯基吲哚的新方法,合成了9个目标化合物,其中8个为新化合物,其结构经¹H NMR, ¹³C NMR和HR-MS(ESI)表征。     

The Development of a New Approaches to the Synthesis of Polyfunctional Phosphorylated Cyclopropanes

Abstract

The report presents the study of cycloaddition reactions of phosphorylnitrile xides to dipolarophils of cyclopropene senes and development of a new methods for synthesis of cyclopropanols and cyclopropylamines bearing phospharyl moiety.     

Synthesis of New Polysubstituted Indolizines from Pyridine,Bromonitromethane, and Dialkyl Acetylenedicarboxylates

An efficient and novel approach to the synthesis of dialkyl 1‐nitroindolizine‐2,3‐dicarboxylates has been described. A one‐pot reaction between a pyridine, dialkyl acetylendicarboxylate, and bromonitromethane leads to dialkyl 1‐nitroindolizine‐2,3‐dicarboxylates in good yields.     

新多取代吡啶类化合物的合成及生物活性

为寻找具有农用生物活性的新颖化合物,以2-氰基硫代乙酰胺为起始原料经由三步反应,设计并合成出了一系列新颖的多取代吡啶衍生物2-甲基-5-氰基-6-炔丙硫基-4-(2-呋喃基或噻吩基)吡啶-3-甲酸甲酯或乙酯和6-甲基-5-乙酰基-2-炔丙硫基-4-(2-呋喃或噻吩基)吡啶-3-乙腈.所有新化合物均经过1H NMR和元素分析确证.初步生物活性测定表明:化合物7有一定的除草和杀菌活性.     

Synthesis of Polysubstituted 1,4-Diazacycloheptan-5-ones. 1. Synthesis and Conformational Investigation of Polysubstituted 4-Piperidones

A series of tri- and tetrasubstituted 4-piperidones and their bicyclic analogs has been synthesized. It was established by ¹H NMR spectroscopy that all the piperidones obtained have the chair conformation in solution with equatorially disposed substituents.     

多取代环丙烷化合物的合成研究

具有环丙烷结构的化合物是一种重要的生物代谢中间体,广泛存在于许多植物霉菌和细菌等微生物体内。三元环是一种具有很好生物活性的结构单元。三元环的反应活性不仅因为它具有类似于链状双键的化学性质,同时还具有易重排的特点,例如,由三元碳环到四元碳环、五元碳环和七元碳环的扩环反应及四元碳环到三元碳环的环收缩反应,据文献报道,给体－受体同碳取代的三元环和多取代的三元环也是一种重要的合成单元。     

Catalytic Enantioselective Synthesis of Highly Functionalized Difluoromethylated Cyclopropanes

The first catalytic asymmetric synthesis of highly functionalized difluoromethylated cyclopropanes is described. The method, based on a rhodium‐catalyzed cyclopropanation of difluoromethylated olefins, gives access to a broad range of cyclopropanes bearing ester, ketone, or nitro functional groups. By using Rh₂((S )‐BTPCP)₄ as a catalyst, the corresponding products were obtained in high yields and high diastereo‐ and enantioselectivities (up 20:1 d.r. and 99 % ee ). This methodology allowed preparation of enantioenriched difluoromethylcyclopropanes for the first time.     

多取代吡唑合成最新研究进展

吡唑是一类重要的五元含氮杂环化合物,广泛存在于许多天然产物、生物活性分子和药物分子中,而且是一类重要的有机合成中间体.因此,近年来吡唑及其衍生物的合成引起了科学家们的极大兴趣,并得以迅速发展.对近年来多取代吡唑的合成新方法进行了综述,以期对相关领域的研究起到一定的辅助与推动作用.     

新型多取代2,7-萘二甲酸二乙酯的合成

以4,6-二甲基-2-甲氧基-1,3-苯二甲酸二乙酯为原料,经Micheal加成、环化、溴化、消除等5步反应,合成新型的多取代2,7-萘二甲酸二乙酯.该合成路线步骤少,收率高,反应条件温和.产物中的4个新化合物的结构均经元素分析、核磁共振、红外光谱和质谱确证.