Synthesis of Substituted Hexahydroindazoles

Substituted hexahydroindazoles were obtained by the reaction of 6-arylidene-2-furfurylidene-cyclohexanones with phenylhydrazine. It was concluded by means of the NMR spectra that azacyclization takes place regioselectively with participation of the arylidenecyclohexanone fragment. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 986–990, July, 2005.     

Synthesis of Unsymmetrically Substituted Porphyrins

Four new unsymmetrically substituted porphyrins have been synthesized using 10-aryl-a,c-biladiene dihydrobromide as key intermediate.     

Synthesis of Substituted Terphenyl Derivatives

Several substituted terphenyl derivatives were prepared following two synthetic routes with five steps. Condensation of 4‐amino‐3‐bromo‐benzotrifluoride with 4‐(methylthio) phenyl boronic acid in the presence of sodium carbonate and palladium triphenylphosphine in toluene gave 4‐amino‐3‐(4‐methylthiophenyl)‐benzotrifluoride. Treatment of this compound with osmium tetroxide in the presence of 4‐methyl morpholine‐N‐oxide yielded the corresponding sulfone, which was converted into the iodo derivative using sodium nitrite. The iodo derivative thus obtained was treated first with propylmagnesium chloride and triethylborane and subsequently with hydroxylamine‐O‐sulfonic acid to furnish the target compounds.     

苯烷基取代的对苯二酚的合成

以1,4－二甲氧基苯为原料,经傅氏酰基化反应、黄鸣龙改良还原、醚键的断裂三步反应合成了3个苯烷基对苯二酚。产物的结构由元素分析、IR和^1H NMR确认。     

取代的丙烯酸乙酯的固相合成研究

近十多年来,利用聚合物试剂进行非序列性的固相普通有机台成已有诸多报道。固相合成法的突出特点是操作简单,分离容易,由于高分子效应,所以常常可以使反应条件温和或者使反应具有较高的选择性。     

Selectively Dendronized Cellulose: Synthesis and Characterization

Selectively dendronized cellulose at C‐6 was synthesized homogeneously (in DMSO) and heterogeneously (in methanol) by the conversion of 6‐azido‐6‐deoxy cellulose (degree of substitution, DS 0.75) with polyamidoamine (PAMAM) dendrons possessing an ethynyl focal moiety via the copper‐catalyzed Huisgen reaction (click reaction) under mild conditions. First to third generation of PAMAM‐triazolo cellulose derivatives with DS values of up to 0.69 could be prepared, which are soluble in organic solvents (DMSO, DMF) and in water. The novel biopolymer derivatives were characterized by elemental analysis, FTIR, and NMR spectroscopic methods, showing no impurities and no conversion at the secondary positions.

     

Synthesis of Highly Substituted Hexahelicenes

C₂‐Symmetric hexahelicenes 3a – 3g , which bear four or six alkoxy chains, were prepared in eight‐to‐nine reaction steps in high overall yields. The final step consisted of a twofold oxidative photocyclization of the corresponding 2,7‐bis(2‐phenylethenyl)naphthalenes. Long (and branched) chains provide a good solubility and processability, which is a prerequisite for applications in organic synthesis and materials science.     

Synthesis of Substituted 2,2,4,4-Tetramethylcyclobutanones

Some of the alkyl substituted 2,2,4,4-tetramethylcyclobutanones were synthesized by conventional methods.     

取代肉桂酰甘氨酸酯的合成

在N-甲基吡咯烷酮(NMP)促进下,取代肉桂酸(1a^1g)与二氯亚砜(SOCl2)在20℃酰氯化反应0.5 h,再加入甘氨酸乙酯盐酸盐,在40℃下酰胺化反应4 h,n(取代肉桂酸)/n(SOCl2)/n(甘氨酸乙酯盐酸盐)=1.0/1.2/1.4,合成了一系列取代肉桂酰甘氨酸乙酯(2a^2g),其结构经1H NMR、13C NMR、IR和MS(EI)确证。并探讨了NMP促进取代肉桂酰甘氨酸乙酯反应可能的机理。     

选择性聚乙二醇化赖氨酸的合成

以单甲氧基聚乙二醇(mPEG)和Fmoc-Lys(Boc)-OH(1)为主要原料,经过羧基苄酯化、侧链Boc脱除、ε-氨基丁二酸酐修饰得到功能化的赖氨酸化合物N-α-芴甲氧羰基-N-ε-(γ-氧代丁酸)-L-赖氨酸苄酯(4);1和4分别与mPEG在偶联剂D IC/HOB t的作用下联接,最终分别实现了赖氨酸主链和侧链的mPEG定点修饰,合成了新型的N-α-芴甲氧羰基-N-ε-(γ-氧代丁酸聚乙二醇酯)-L-赖氨酸苄酯(5,总收率52.6%)和N-ε-叔丁氧羰基-N-α-芴甲氧羰基-L-赖氨酸聚乙二醇酯(6,收率93.7%),其结构经1H NMR,IR和MS表征。     

A Modular Synthesis of Substituted Cycloparaphenylenes

Herein, we report a modular synthesis providing access to substituted cycloparaphenylenes (CPPs) of different sizes. A key synthon introducing two geminal ester units was efficiently prepared by [2+2+2] cycloaddition. This building block can be conveniently converted to macrocyclic precursors controlling the ring size of the final CPP. Efficient reductive aromatization through single-electron transfer provided the substituted nanohoops in a straightforward manner. The tBu ester substitution pattern enables a tube-like arrangement in the solid-state governed by van der Waals interactions that exhibits one of the tightest packings of CPPs in tube direction, thus opening new avenues in the crystal design of CPPs.     

一锅法简便合成取代苯氧基苯乙酮

探讨了聚合物支载的铬（Ⅵ）氧化剂、过溴离子及取代苯氧基离子于单锅中以1－苯乙醇为底物,合成苯氧基苯乙酮的方法,并与分步合成法相比较。实验表明,此合成方法具有操作简便、反应条件温和、无须分离中间体、且产率较高等优点,并探索了温度、溶剂、树脂的用量等对一锅法产率的影响。     

Convenient Synthesis of Piperazine Substituted Quinolones

A series of 1‐[(4‐hydroxy‐2‐oxo‐1‐phenyl‐1,2‐dihydroquinolin‐3‐yl)carbonyl]‐4‐(substituted) piperazines 3a–c and methyl 2‐[(4‐hydroxy‐2‐oxo‐1‐phenyl‐1,2‐dihydroquinolin‐3‐yl)carbonylamino] alkanoates 5a–d has been developed by the direct condensation of ethyl [4‐hydroxy‐2‐oxo‐1‐phenyl‐1,2‐dihydro‐3‐quinoline] carboxylate 2 with N ¹‐monosubstituted piperazine hydrochlorides or amino acid ester hydrochloride in the presence of triethyl amine. The quinolone amino acid esters 5a–d were the key intermediate for the preparation of a series of 1‐[2‐((4‐hydroxy‐2‐oxo‐1‐phenyl‐1,2‐dihydroquinolin‐3‐yl)carbonylamino)alkylcarbony]‐4‐substituted piperazine derivatives 8–11 (a‐d) via azide coupling method with amino acid ester hydrochloride.     

Synthesis of Some Substituted 1,3,2-Oxazaphosphorinanes

Abstract

To study the effect of statistically controlled associate dia-stereoisomerism (SCADA), the optical isomers of some derivatives of 2-amino-2-oxo-1,3,2-oxazaphosphorinane, containing the residues of L-α-aminoacids, were synthesized. The magnitude of chemical shift nonequivalence (Δδ) in ³¹P NMR-spectra of diastereomeric mixtures was maximum for isomeric derivatives of valine; the dependence of Δδ³¹P on their concentration was investigated.