4490-10-2Relevant academic research and scientific papers
Formamide-Catalyzed Nucleophilic Substitutions: Mechanistic Insight and Rationalization of Catalytic Activity
Hilt, Gerhard,Huy, Peter H.,Kohlmeyer, Corinna,Sch?fer, André
, p. 11567 - 11577 (2020/11/17)
Herein, detailed mechanistic investigations into formamide-catalyzed nucleophilic substitution (SN) of alcohols are reported. Alkoxyiminium chlorides and hexafluorophosphates were synthesized and characterized as a key intermediate of the catalytic cycle. The determination of reaction orders and control experiments indicated that the nucleophilic attack of the formamide catalyst onto the reagent BzCl is the rate-determining step. Linear free energy relationship revealed a correlation between the quantified Lewis basicity strength of formamides by means of 11B NMR spectroscopy and their catalytic activity in SN-transformations. The observed difference in catalytic ability was attributed to the natural bond order charge, dipole moment, and Sterimol parameter B5. Importantly, this rationalization enables the prediction of the capacity of formamides to promote SN-type transformations in general.
Thiogeraniol preparation method
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Paragraph 0018; 0019; 0020; 0021; 0022, (2017/08/25)
The invention relates to the field of fine chemistry, and concretely relates to a thiogeraniol preparation method. The method comprises the following steps: carrying out a reaction on a raw material thiogeraniol with triphenyl phosphine in a solvent carbon tetrachloride, carrying out a reaction on the above obtained reaction product 1 with thiourea in a solvent anhydrous ethanol, carrying out a reaction on the above obtained reaction product 2 and p-toluenesulfonic acid to form a salt, and decomposing the salt to obtain a final product. The method has the advantages of avoiding of generation of isomers due to prevention of high-temperature distillation purification in a key purification step, easiness in obtaining of the raw material, low cost, short synthesis short, easiness in realization of reaction conditions, convenient and easy purification process, high yield, and realization of obtaining of highly-pure thiogeraniol.
Copper-free arylation of 3,3-disubstituted allylic halides with triazene-softened aryl Grignard reagents
Xu, Lijun,Liu, Zhubo,Dong, Weipeng,Song, Jinyu,Miao, Maozhong,Xu, Jianfeng,Ren, Hongjun
supporting information, p. 6333 - 6337 (2015/06/08)
A copper-free allylic arylation reaction between 3,3-disubstituted allylic halides and triazene-softened aryl Grignard reagents has been developed. This protocol presents a direct and efficient way to construct both α- or γ-isomers with high regioselectivity under environmentally benign conditions. Various functional groups can be tolerated in the reaction and the products are of high value for multiple synthetic applications. The α- and γ-isomers can be converted to the corresponding 3H-indole and indole derivatives in multigram scale respectively.
Pivaloyl chloride/DMF: a new reagent for conversion of alcohols to chlorides
Dubey, Abhishek,Upadhyay, Arun K.,Kumar, Pradeep
experimental part, p. 744 - 746 (2010/04/05)
An efficient procedure for conversion of alcohols into the corresponding chlorides is described. Pivaloyl chloride/DMF complex is employed as a mild and inexpensive reagent. A possible reaction mechanism is proposed.
Aromatic cation activation of alcohols: Conversion to alkyl chlorides using dichlorodiphenylcyclopropene
Kelly, Brendan D.,Lambert, Tristan H.
supporting information; experimental part, p. 13930 - 13931 (2009/12/25)
(Chemical Equation Presented) A novel paradigm for the activation of alcohols toward nucleophilic displacement via formation of cyclopropenium ethers is described. The conversion of a range of alcohol substrates to the corresponding alkyl chlorides occurs rapidly upon treatment with 3,3-dichloro-1,2-diphenylcyclopropene. 1H NMR data support the intermediacy of a cyclopropenium intermediate, and the reaction is demonstrated to proceed primarily via the SN2 mechanism for 1-phenylethanol. A total of 12 examples of substrate scope are provided.
Synthesis and antimycobacterial activity of agelasine E and analogs
Bakkestuen, Anne Kristin,Gundersen, Lise-Lotte,Petersen, Dirk,Utenova, Bibigul T.,Vik, Anders
, p. 1025 - 1033 (2007/10/03)
Agelasine E, previously isolated from the marine sponge Agelas nakamurai, has been synthesized for the first time, together with analogs with various terpenoid side chains. Treatment of N6-methoxy-9-methyl-9H-purin-6- amine with allylic bromides gave the desired 7,9-dialkylpurinium salts together with minor amounts of the N6-alkylated isomer. The N 6-methoxy group was finally removed reductively. 1H- 15N HMBC and 1H-15N HSQC NMR spectroscopy gave additional information on tautomerism and charge delocalization in the purine derivatives studied. The heterocyclic products were screened for activity against Mycobacterium tuberculosis and agelasine analogs carrying a relatively long terpenoid substituent in the purine 7-position and a methoxy group at N-6 were potent inhibitors of bacterial growth. Since agelasine analogs with the geranylgeranyl chain at N-7 exhibited antimicrobial activity, several strategies for synthesis of geometrically pure (2E,6E,10E)-geranylgeranyl bromide from geranyllinalool were evaluated. The Royal Society of Chemistry 2005.
Fragrance precursor compounds
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Example 5, (2008/06/13)
Compounds having formula (I) in which n is 1, 2 or 3 and R1to R6represent, independently, branched or unbranched, substituted or unsubstituted alkyl-, alkenyl-, alkinyl-, cycloalkyl-, cycloalkenyl- or aromatic-radicals or hydrogen wherein these radicals may in addition contain one or more —O— and/or (a)—groups, whereby one or two rings can be built by the combination of the respective R1to R6and this/these ring(s) can be further substituted by an alkyl-group, in which X is either O and R7represents a radical of an alcohol or phenol R7OH, or X is N and R7represents the radical of an amine R7′R7″NH, whereby R7′and R7″represent independently, branched or unbranched, substituted or unsubstituted alkyl-, alkenyl-, alkinyl-, cycloalkyl-, cycloalkenyl- or aromatic radicals or either R7′R7″may be hydrogen, whereby the amine is a fragrant amine or the amine has more than 9 C atoms, whereby R7of the alcohol or phenol and R7′and/or R7″of the amine, respectively, may further contain at least one remaining part C(OH)R1R2—CR3R4—(CR5R6)n—CO— of formula (I), are useful as precursors for the delivery of odoriferous and/or antibacterial compounds in cosmetic compositions, cosmetic products, air fresheners, hard surface cleaners or laundry products.
Rhodium(I)-catalyzed addition of phenols to dienes. A new convergent synthesis of vitamin E
Bienaymé, Hugues,Ancel, Jean-Erick,Meilland, Pierre,Simonato, Jean-Pierre
, p. 3339 - 3343 (2007/10/03)
A highly convergent and atom-economical synthesis of (dl)-[α]- tocopherol (vitamin E) is proposed, the realization of which was made possible by the discovery of the regioselective Rh(I)-catalyzed arylation of β-springene with trimethylhydroquinone. Other phenolic compounds and 2- substituted-1,3-dienes were shown to undergo this transformation. (C) 2000 Elsevier Science Ltd.
