Topic
Substituent
About: Substituent is a research topic. Over the lifetime, 42877 publications have been published within this topic receiving 516716 citations. The topic is also known as: side chain & side group.
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TL;DR: A series of p -substituted phenyldimesitylboranes has been synthesized by reaction of dimesity lboron fluoride with appropriately substituted phenyllithium derivatives.
100 citations
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TL;DR: In this paper, the authors show that the presence of a 3-hydroxyl group in the flavonoid molecule has little effect on the complex-forming ability and the nature of the sugar substituent has no influence on the reaction.
100 citations
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TL;DR: In this article, a review of the developments in imidazole chemistry is presented, including the properties of the 1-acylimidazoles (imidazolides), which are extremely reactive in such nucleophilic reactions as hydrolysis and alcoholysis.
Abstract: Publisher Summary This chapter reviews the developments in imidazole chemistry and discusses condensed imidazoles (such as benzimidazole, purines, etc), and compounds containing reduced imidazole rings The methods for the syntheses of the imidazole ring system are also presented Physical properties of imidazole and its derivatives such as dipole moments; melting points, boiling points, and solubilities; acid and basic strength; crystal structure; UV spectra; IR and Raman spectra; NMR spectra; mass spectrometry; electron spin resonance; optical rotatory dispersion and polarography; chromatography; thermodynamic data; and quantum mechanical calculations are described In addition, the chemical properties such as structure; aromatic character and reactivity; electrophilic substitution reactions; nucleophilic attack; reactions involving radicals; reactions of substituents on ring carbon atoms; reactions of substituents on ring nitrogen atoms; and miscellaneous properties of imidazole and its derivatives are illustrated Most of the reactions and properties of 1-substituted imidazoles have been discussed Apart from the utilization of the readily removable benzyl substituent in synthetic procedures leading to 2-substituted imidazoles, perhaps the most exciting advances have stemmed from the reactions of the 1 -acylimidazoles (imidazolides), which are extremely reactive in such nucleophilic reactions as hydrolysis and alcoholysis
100 citations
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TL;DR: In this paper, Grignard reactions on nickel meso-formyl octaethyl porphyrin (1a) yield methyl and phenyl carbinols, which are readily oxidised to the 1,4-diporphyryrinylbuta-1,3-diyne.
Abstract: Grignard reactions on nickel meso-formyloctaethylporphyrin (1a) yield methyl and phenyl carbinols. The former is readily dehydrated to the meso-vinyl derivative, which by hydrogenation yields the meso-ethyl analogue, and by bromination and dehydrobromination affords the meso-ethynyl compound. The latter is readily oxidised to the 1,4-diporphyrinylbuta-1,3-diyne. Reaction of sulphuric acid with the meso-phenyl carbinol gives a meso-benzyl derivative in which one β-ethyl group has been dehydrogenated to give a β-vinyl substituent. Attempts to form a carbene from (1a) with triethyl phosphite gave the meso-propenyl compound and with boron trifluoride and zinc amalgam gave the meso-formyloxy derivative, which is transformed readily into the meso-methoxy compound. Mechanisms for these novel reactions are suggested.
100 citations
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14 Apr 1969
TL;DR: In this article, the authors present a comparison of different types of conformations of high-and low-weighted ALKYL-SUBSTITUTed PHENOL and ALDEHYDEHDE.
Abstract: PRODUCTS OF THE CONDENSATION OF (1) A HIGH MOLECULAR WEIGHT ALKYL - SUBSTITUTED HYDROXYAROMATIC COMPOUND WHOSE ALKYL SUBSTITUENT HAS UPWARD FROM 40 TO 20,000 AND ATOMS, (2) A LOWER MOLECULAR WEIGHT ALKYL-SUBSTITUTED PHENOL WHOSE ALKYL-SUBSTITUENT HAS 2 TO 20 CARBON ATOM, (3) AN AMINE HAVING TWO PRIMARY AMINO (-NH2) GROUPS AND (4) AND ALDEHYDE IN THE RESPECTIVE MOLAR RATIO OF REACTANTS OF 2.0:0.7-1.4-2.0:2.8-4.0, ARE NOVEL ASHLESS-TYPE (METAL FREE) MINERAL-OIL SOLUBLE ADDITON AGENTS HAVING DISPERSANT DETERGENT AND ANTI-OXIDANT FUNCTIONSAFFORDING ANTI-SLUGE AND ANTI-VARNISH DEPOXITION AND CORROSION INHIBITION IN CRANKCASE LUBRICATING COMPOSITIONS SUBJECTED TO LOW OR HIGH TEMPERATURE IN-SERVICE USE. SUCH CONDENSATION PRODUCTS ARE PREPARED EITHER BY SINGLE STEP REACTION CONDUCTED BY SUBJECTING ALL FOUR OF THE REACTANTS IN THE STATED MOLAR RATIO OF REACTANTS TO A SINGLE CONDENSATION REACTION UNDER KNOWN MANNICH CONDENSATION REACTION CONDITIONS OR BY A TWO STEP REEACTION WHEREIN REACTANTS (1), (3) AND (4) ARE FIRST SUBJECTED TO MANNICH CONDENSATION CONDITIONS IN THE RESPECTIVE MOLAR RATIO OF 2:1.4-2.0:1.4-2.0 AND THE ESULTING FIRST STEP PRODUCT IS FURTHER CONDENSED WITH REACTANTS (2) AND (4) USED IN THE ESPECTIVE MOLAR RATIO OF 0.7-1.0:1.4-2.0.
100 citations