摘要:
The invention relates to the use of substances for the production of anions suitable for charge transfer reactions in mass spectrometers, particularly for the fragmentation of multiply positively charged biopolymer ions by electron transfer or for charge reduction by proton transfer. Diketones, particularly α-diketones, are proposed as a newly found class of substances which can be used both for the production of radical anions for electron transfer dissociations (ETD) with a high yield of fragment ions and also for the production of non-radical anions for the charge reduction of multiply charged analyte ions by proton transfer reactions (PTR). These substances have favorable properties in terms of their handling and the associated analytical methods: they are largely nontoxic, cover a favorable range of molecular masses, and their volatility means that they can be stored in unheated containers outside of the vacuum system, which facilitates the refilling of the containers.
摘要:
The presently disclosed subject matter demonstrates that a spin state which has zero magnetic resonance signal, but an extremely long lifetime, can be used to store magnetization, which can then be recovered into an observable transition. Coupled with hyperpolarization techniques, this permits the preparation of a wide range of contrast agent molecules for use in magnetic resonance imaging (MRI) techniques that have long effective relaxation time.
摘要:
A method of synthesizing organic molecules is provided, wherein the method comprises providing an electrophilic educt, providing an ionic liquid comprising a carbanion, and synthesizing the organic molecules by mixing the electrophilic educt and the ionic liquid.
摘要:
The invention relates to the use of substances for the production of anions suitable for charge transfer reactions in mass spectrometers, particularly for the fragmentation of multiply positively charged biopolymer ions by electron transfer or for charge reduction by proton transfer. Diketones, particularly α-diketones, are proposed as a newly found class of substances which can be used both for the production of radical anions for electron transfer dissociations (ETD) with a high yield of fragment ions and also for the production of non-radical anions for the charge reduction of multiply charged analyte ions by proton transfer reactions (PTR). These substances have favorable properties in terms of their handling and the associated analytical methods: they are largely nontoxic, cover a favorable range of molecular masses, and their volatility means that they can be stored in unheated containers outside of the vacuum system, which facilitates the refilling of the containers.
摘要:
A method of synthesizing organic molecules is provided, wherein the method comprises providing an electrophilic educt, providing an ionic liquid comprising a carbanion, and synthesizing the organic molecules by mixing the electrophilic educt and the ionic liquid.
摘要:
Oxidations of hydrocarbons, cycloalkanes and alkenes, arylalkanes, and a variety of other organic substrates are accomplished by cobalt-N-hydroxysuccinimide co-catalyzed reactions with dioxygen under unusually mild, near ambient conditions of temperature and pressure. The improved safety of the oxidation method and the high yields of product obtained make use of a unique combination of cobalt (II) complexes with N-hydroxysuccinimide. These autoxidation reactions do not have prolonged initiation times. Many of these reactions can be safely performed under normal chemical laboratory conditions and do not require specialized equipment or reagents.
摘要:
The object of the invention relates to a development of a new musk-feeling fragrance material which is a highly scenting musk-feeling fragrance, and is to provide a fragrance composition which, when added to fragrances or cosmetics, can improve the fixative property and express a high performance and excellent musky aromatic quality.A fragrance composition is prepared using, as the active ingredient, a mixture of (R)-form of optically active muscone with (S)-form of optically active muscone with the mixing ratio thereof within the range of from 90:10 to 95:5 (weight ratio) in terms of weight ratio, or a mixture of (R)-form of optically active muscone with (S)-form of optically active muscone with the mixing ratio thereof within the range of from 75:25 to 80:20 (weight ratio) in terms of weight ratio.
摘要:
Disclosed is a process for preparing a β-diketone compound such as 2,6-dimethyl-3,5-heptanedione, which comprises reacting an ester compound such as an alkyl isobutyrate with a ketone compound such as 3-methylbutanone in the presence of an alkali metal alkoxide as a catalyst. The process comprises a step 1 in which an ester compound CR1R2R3COOQ is reacted with a ketone compound CR4R5R6COCH2R7 using an alkali metal alkoxide catalyst to give a β-diketone compound CR1R2R3COCHR4R5R6. (In the formulae, R7 is hydrogen or an alkyl group of 1 to 4 carbon atoms while others are each independently hydrogen or an alkyl group of 1 to 3 carbon atoms, and at least one of R1 to R6 is hydrogen.)
摘要翻译:公开了一种制备2,6-二甲基-3,5-庚二酮的β-二酮化合物的方法,该方法包括使异氰酸烷基酯等酯化合物与3-甲基丁酮等酮化合物在 碱金属醇盐作为催化剂。 该方法包括步骤1,其中酯化合物CR 1 R 2 SO 3 COOQ与酮化合物CR 4 使用碱金属醇盐催化剂,得到β5,R 6,R 5,R 7,R 7, 二酮化合物CR 1 R 2 R 2 SO 3 R 4 R 5 R 5 SUP> 6 SUP>。 (式中,R 7为氢或1〜4个碳原子的烷基,其余各自独立地为氢或1〜3个碳原子的烷基,R 1〜 SUP> 1至R 6是氢。)
摘要:
A method for producing &agr;-dicarbonyl compounds of formula (I): wherein R1 and R2, independently of each other, mean C1-6-alkyl. In the method, an &agr;,&bgr;-unsaturated ketone of formula (II): wherein R1 and R2 have the meaning above and R3 and R4, independently of each other, mean hydrogen, C1-6-alkyl or di-C1-6-alkylamino, is reacted with ozone in the absence of a catalyst and the resultant ozonide is treated reductively.