Alcohol Homologues Research Articles

Nickel-Catalyzed Deoxygenative Amidation of Alcohols with Carbamoyl Chlorides.

We report a deoxygenative amidation reaction of alcohols with carbamoyl chlorides to afford amides through nickel-photoredox dual catalysis. Good to excellent yields can be obtained even for diverse complex sugar and steroid derivatives. The reaction is scalable, and the synthetic utility of the reaction was demonstrated by the homologation of alcohols to deliver several important γ-amino alcohols and a synthetically challenging bioactive compound intermediate.

Photoredox and NHC Enabled Deoxygenative Alcohol Homologation via Formal 1,2-Addition.

A highly efficient photoinduced iron-catalyzed method has been developed for the direct use of alcohols as surrogates for organometallic reagents in the synthesis of tertiary alcohols. This method can be applied to both primary and secondary alcohols with diverse structures, enabling their reaction with aryl ketones under mild conditions. A variety of functional groups, including those that are typically reactive under conventional tertiary alcohol synthesis conditions, are compatible. Mechanistically, this reaction proceeds through the direct addition of the radical to the carbonyl pathway.

Synthesis of hierarchically porous zirconium-based metal-organic framework@silica core-shell stationary phase through etching strategy for liquid chromatography

Metal organic frameworks (MOFs) show promise to be employed as stationary phase for high performance liquid chromatography (HPLC), however, the microporous structures of MOFs seriously restrict the diffusion and mass transfer of solute molecules, leading to a low column efficiency. In this paper, the fabrication of hierarchically porous UiO-66@SiO2 (HP- UiO-66@SiO2) core-shell microspheres via H2O2 etching has been proposed as a viable approach to enhance the separation performance of MOFs-based columns for HPLC. Through the direct treatment of the preliminary prepared UiO-66@SiO2 microspheres with H2O2 etching, HP-UiO-66@SiO2 core-shell microspheres were successfully synthesized with an enlarged pore size of up to 9 nm, facilitating efficient mass transfer in chromatographic separation. The prepared HP-UiO-66@SiO2 core-shell microspheres were then explored as stationary phase in HPLC to separate the nonpolar alkyl benzene homologues, the polar aromatic alcohol homologues and the xylene isomers. The results indicated that the baseline separations of these solutes were achieved successfully with narrow peak width and higher resolution than the UiO-66@SiO2 column. The HP-UiO-66@SiO2 column exhibited superior separation performance, reaching a maximum plate number of 134,459/m for fluorene, and showing good reproducibility. As a result, this template-free approach suggests that the fabrication of hierarchically porous MOFs@silica core-shell microspheres is a successful approach to enhance the column efficiency of MOFs-based columns in HPLC.

Highly Selective Wearable Alcohol Homologue Sensors Derived from Pt-Coated Truncated Octahedron Au.

Unhealthy alcohol inhalation is among the top 10 causes of preventable death. However, the present alcohol sensors show poor selectivity among alcohol homologues. Herein, Pt-coated truncated octahedron Au (Ptm@Auto) as the electrocatalyst for a highly selective electrochemical sensor toward alcohol homologues has been designed. The alcohol sensor is realized by distinguishing the electro-oxidation behavior of methanol (MeOH), ethanol (EtOH), or isopropanol (2-propanol). Intermediates from alcohols are further oxidized to CO2 by Ptm@Auto, resulting in different oxidation peaks in cyclic voltammograms and successful distinction of alcohols. Ptm@Auto is then modified on wearable glove-based sensors for monitoring actual alcohol samples (MeOH fuel, vodka, and 2-propanol hand sanitizer), with good mechanical performance and repeatability. The exploration of the Ptm@Auto-based wearable alcohol sensor is expected to be suitable for environmental measurement with high selectivity for alcohol homologues or volatile organic compounds.

Simulation of gas chromatographic separation based on random diffusion

色谱分离过程中的粒子扩散问题是色谱动力学研究的基础,深入理解粒子的扩散行为对优化分离操作条件、提升色谱性能和开发新型色谱柱尤为关键。现有的模拟方法多集中于局部过程的热力学研究,而整体的扩散分离过程报道并不多见。为此,该文基于微尺度受限空间内随机扩散的方法,通过动态追踪粒子的运动轨迹,实现粒子在气相色谱开管柱内的扩散全过程模拟。基于前期烷烃同系物的分离模拟研究,结合Kovats保留指数,分别建立了吸附步数与温度、吸附步数与碳数的函数关系,由此获得不同类型的同系物在不同温度条件下的分离参数系统。以醇类同系物的分离验证模拟的可靠性,结果表明保留时间的相对误差基本控制在5%以内,而峰宽相对误差在0.75%~60%之间。峰宽误差较大的原因在于:(1)参数化计算过程中未能充分迭代以及使用外推法;(2)模型中忽略了醇分子之间的氢键作用。该文提出的模拟方法虽然可以准确地预测色谱保留时间以及合理描述色谱峰的基本形貌特征,但尚有进一步发展空间,特别是增加对分子间相互作用的细节处理,例如可参考分子力学的方法建立分子间势函数和吸附步数的关系,利用分子力学计算的能量来取代参数化的吸附步数,从而实现更为精确的分离过程模拟。总体而言,该文所提出的模拟方法为优化色谱分离操作条件和开发新型色谱分离技术提供了有价值的参考。

English

In order to investigate the morphology and composition of cuticular waxes on the spikes and leaves at different plant growth stages, the glossy variety (Changwu9945-10) and glaucous variety (L955195) of wheat (Triticum aestivum) were selected. Scanning electron microscopy (SEM) revealed that the morphology of cuticular wax crystals changed constantly throughout plant growth, and the wax crystals of spike (glume) and leaf surfaces were tubules and platelets. Tubule wax crystals could formed on the glumes within a few days, but took longer time to form on the leaf surface. Gas Chromatography-Mass Spectrometry (GC-MS) analysis displayed five different compound classes on the extracts of the spikes and leaves, including alkane homologues (C25–C33), alcohol homologues (C22–C32), aldehyde homologue (C24–C30) and diketones (C31). Furthermore, the content of five compound classes changed at the different development stages in the cultivars. The total wax content at each development stage of L955195 was higher than that of Changwu9945-10. Interestingly, OH-β-diketones identified only in the glaucous variety (L955195). Diketone was the major compound class that caused the changes during the spike growth period, while alcohols were the major compound classes that caused the changes during the leaf growth period. At the same time, there were also dramatic changes in the chain length distribution of these compositions. Therefore, based on the above results, this study provided comprehensive information for wheat cuticular waxes and advanced the knowledge for development of wheat waxes in the future. © 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers © 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers© 2021 Friends Science Publishers©

The impact of the length of alkyl chain on the behavior of benzyl alcohol homologues - the interplay between dispersive and hydrogen bond interactions.

In this work, we examined the effect of the length of alkyl chain attached to the benzene ring on the self-assembling phenomena for a series of phenyl alcohol (PhA) derivatives, from phenylmethanol (benzyl alcohol) to 7-phenyl-1-heptanol, by means of X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared (FTIR) spectroscopy, and Broadband Dielectric Spectroscopy (BDS) methods. XRD data in the reciprocal and real spaces showed a gradual increase in the local order with the elongation of the alkyl chain. However, the position and full width at half maximum of the main diffraction peak exhibited a non-systematic behavior. To better understand this fact, PhAs were subjected to FTIR spectroscopic studies. These investigations revealed that the association degree and the activation energy of dissociation increase as the alkyl chain length grows. On the other hand, BDS data showed a non-monotonic variation in the Kirkwood correlation factor with increasing length of the alkyl chain, indicating a competition between interactions of the non-polar and polar parts of the molecules in the studied PhAs. Finally, it was also found that the molar surface entropy for PhAs increases with the number of methylene groups, approaching values reported for alkanes, which indicates suppression of the surface order for PhAs with a long alkyl chain. This variability of the various parameters as a function of the length of the side chain shows that the interplay between soft interactions has a strong impact on the local structure and intra and intermolecular dynamics of the studied PhAs.

Efficient Identification for Alcohol Homologues and Hyperthermy Based on Coordination Polymer Multiple Structural Transformations.

Recently, coordination polymer materials are of high interest due to the potential applications for chemical sensing and luminescent materials. In this work, we designed a photofluorescence coordination polymer material based on a donor-metal-acceptor structure. The donor-metal-acceptor architecture showed unusual multiple environmental responsiveness accompanied by a great change of fluorescence behaviors. Generally, organic homologue molecules are not easily distinguished by coordination polymer sensors because they have similar molecular structures and interaction sites. However, using the feature of multiple structural transformations, the accurate identification for organic homologue molecules can be realized, especially in a short time to quickly identify MeOH in other alcohol homologues (even in mixed atmospheres with only 10% MeOH). The visualization transformation of fluorescence can also be realized by single crystal to single crystal thermal-induced coordination bond ON/OFF behavior. The reversible structure conversion strategy provides new ideas for the accurate identification of organic homolog molecules or external environmental stimuli.

Synthesis and optimization of SiO2@SiO2 core-shell microspheres by an improved polymerization-induced colloid aggregation method for fast separation of small solutes and proteins

Recently, superficially porous particles (SPPs) have been intensively studied and employed for highly efficient and fast separations. In this paper, the SiO2@SiO2 SPPs were synthesized by an improved polymerization-induced colloid aggregation (PICA) method using urea-formaldehyde polymer as the template. The agglomeration of silica core during modification with ureidopropyltrimethoxysilane (UPS) can not only be avoided by reflux in neutral ethanol solution, but also the secondary nucleation of the colloidal silica sol can be inhibited via optimizing the reaction conditions including pH, temperature, colloidal silica sol concentration and the reaction time. The shell thickness and pore size of SPPs can be controlled successfully by adjusting the weight ratio of silica core/colloidal silica sol and the particle size of colloidal silica sol, respectively. The SPP-C18 columns packed using octadecyltrichlorosilane (ODS) modified SPPs with different pore sizes were employed to separate small solutes and proteins. The baseline separations of 6 kinds of alkyl benzenes and 5 kinds of aromatic alcohol homologues were achieved within 4 min by the SPP-C18 column with 8 nm pore size. Compared with the commercial BEH-C18 column, more than 50,000/m of the plate number of propylbenzene was obtained, and the former provided higher column efficiency to separate small solutes than the latter. Meanwhile, 6 kinds of proteins were also separated completely within 2 min using the SPP-C18 column with 40 nm pore size. In addition, the SPP-C18 capillary column was applied to separate and identify the BSA/HeLa/mouse liver digests with capillary LC-MSMS, respectively. The results indicate that more proteins and peptides can be identified using SPP-C18 capillary column compared with commercial silica-C18 capillary column. The result demonstrates that the prepared SPP-C18 column provides higher column efficiency and the SPPs synthesized with the improved PICA method shows a great potential application for the fast separation of small solutes and proteins.

Boron‐Catalyzed C−C Functionalization of Allyl Alcohols

AbstractTris(pentafluorophenyl)borane‐catalyzed C−C bond functionalization of arylallyl alcohols using donor‐acceptor carbenes is presented. The allylic hydroxyl group is found to assist the product formation by neighboring group participation providing a clue towards mechanistic understanding. This method can also be employed to effect homologation of allyl alcohols to homoallyl alcohols. Overall, this metal‐free transformation presents a novel disconnection strategy towards carbon‐carbon bond scission and formation.magnified image

One and Two-Carbon Homologation of Primary and Secondary Alcohols to Corresponding Carboxylic Esters Using β-Carbonyl BT Sulfones as a Common Intermediate.

Herein we report the efficient one- and two-carbon homologation of 1° and 2° alcohols to their corresponding homologated esters via the Mitsunobu reaction using β-carbonyl benzothiazole (BT) sulfone intermediates. The one-carbon homologation approach uses standard Mitsunobu C-S bond formation, oxidation and subsequent alkylation, while the two-carbon homologation uses a less common C-C bond forming Mitsunobu reaction. In this latter case, the use of β-BT sulfone bearing esters lowers the p Ka sufficiently enough for the substrate to be used as a carbon-based nucleophile and deliver the homologated β-BT sulfone ester, and this superfluous sulfone group can then be cleaved. In this paper we describe several methods for the effective desulfonylation of BT sulfones and have developed methodology for one-pot alkylation-desulfonylation sequences. As such, overall, a one-carbon homologation sequence can be achieved in a two-pot (four step) procedure and the two-carbon homologation in a two-pot (three step) procedure (three-pot; four step when C-acid synthesis is included). This methodology has been applied to a wide variety of functionality (esters, silyl ethers, benzyls, heteroaryls, ketones, olefins and alkynes) and are all tolerated well providing good to very good overall yields. The power of our method was demonstrated in site-selective ingenol C20 allylic alcohol two-carbon homologation.

ChemInform Abstract: One‐Carbon Homologation of Primary Alcohols to Carboxylic Acids, Esters, and Amides via Mitsunobu Reactions with MAC Reagents.

A method is reported for the one-carbon homologation of an alcohol to the extended carboxylic acid, ester, or amide. The process involves the Mitsunobu reaction with an alkoxymalononitrile, followed by unmasking in the presence of a suitable nucleophile. The homologation and unmasking can even be performed in a one-pot process in high yield.

One-Carbon Homologation of Primary Alcohols to Carboxylic Acids, Esters, and Amides via Mitsunobu Reactions with MAC Reagents.

A method is reported for the one-carbon homologation of an alcohol to the extended carboxylic acid, ester, or amide. The process involves the Mitsunobu reaction with an alkoxymalononitrile, followed by unmasking in the presence of a suitable nucleophile. The homologation and unmasking can even be performed in a one-pot process in high yield.

ChemInform Abstract: One‐Carbon Homologation of Primary Alcohols and the Reductive Homologation of Aldehydes Involving a Jocic‐Type Reaction.

AbstractVarious primary aryl, heteroaryl, aliphatic, alicyclic, and allylic alcohols are obtained in a simple two‐step, one‐carbon homologation of primary alcohols or reductive homologation of aldehydes using the Jocic‐type reaction of trichloromethyl carbinols as key reaction.

One‐Carbon Homologation of Primary Alcohols and the Reductive Homologation of Aldehydes Involving a Jocic‐Type Reaction

Abstract(Trichloromethyl)carbinols, which are formed in one operation from either alcohols or aldehydes, can be converted into primary alcohols in a Jocic‐type reaction involving LiBH4. The net result is a convenient two‐step, one‐carbon homologation of primary alcohols or a reductive one‐carbon homologation of aldehydes featuring a broad substrate scope. The method is step‐economical, and it nicely complements established one‐carbon homologation strategies.

Continuous-flow enzymatic resolution strategy for the acylation of amino alcohols with a remote stereogenic centre: synthesis of calycotomine enantiomers

Both enantiomers of calycotomine (R)-5 and (S)-5 were prepared through the CAL-B-catalysed asymmetric O-acylation of N-Boc-protected (6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolin-1-yl)methanol [(±)-3)]. The optimum conditions for the enzymatic resolution were determined under continuous-flow conditions, while the preparative-scale resolution of (±)-3 was performed as a batch reaction with high enantioselectivity (E>200). The resulting amino alcohol (S)-3 and amino ester (R)-4, obtained with high enantiomeric excess (ee=99%), were transformed into the desired calycotomine (S)-5 and (R)-5 (ee=99%). A systematic study was carried out in a continuous-flow system on the O-acylation of tetrahydroisoquinoline amino alcohol homologues (±)-1 to (±)-3 containing a remote stereogenic centre.

ChemInform Abstract: Co2(CO)8-Catalyzed Reaction of Benzylic Acetates with HSiMe3 and CO. A Novel Method for Homologation of Alcohols.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: A New Method of CO2 Activation: Alcohol Homologation with a CO2/H2 Mixture.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Homologation of Allylic Alcohols. An Approach to Cyclic and Acyclic Polyoxygenated Compounds.

Abstract The combination of the Sharpless asymmetric epoxidation reaction with a sulfur ylide mediated synthesis of allylic alcohols from epoxides provides a powerful iterative process for the production of polyoxygenated compounds. The alkene installed in the sulfur ylide reaction has also been used in a number of ring closing metathesis reactions to produce highly oxygenated cyclic compounds.

Generating Multiple Independent Retention Index Data in Dual-secondary Column Comprehensive Two-dimensional Gas Chromatography

A method producing simultaneously three retention indexes for compounds has been developed for comprehensive two-dimensional gas chromatography by using a dual secondary column approach (GC x 2GC). For this purpose, the primary flow of the first dimension column was equally diverted into two secondary microbore columns of identical geometry by means of a three-way flow splitter positioned after the longitudinally modulated cryogenic system. This configuration produced a pair of comprehensive two-dimensional chromatograms and generated retention data on three different stationary phases in a single run. First dimension retention indexes were determined on a polar SolGel-Wax column under linear programmed-temperature conditions according to the van den Dool approach using primary alcohol homologues as the reference scale. Calculation of pseudoisothermal retention indexes in both second dimensions was performed on low-polarity 5% phenyl equivalent polysilphenylene/siloxane (BPX5) and 14% cyanopropylphenyl/86% dimethylpolysiloxane (BP10) columns. To construct a retention correlation map in the second dimension separation space upon which KovAts indexes can be derived, two methods exploiting "isovolatility" relationships of alkanes were developed. The first involved 15 sequential headspace samplings of selected n-alkanes by solid-phase microextraction (SPME), with each sampling followed by their injection into the GC at predetermined times during the chromatographic run. The second method extended the second dimension retention map and consisted of repetitive introduction of SPME-sampled alkane mixtures at various isothermal conditions incremented over the temperature program range. Calculated second dimension retention indexes were compared with experimental values obtained in conventional one-dimensional GC. A case study mixture including 24 suspected allergens (i.e., fragrance ingredients) was used to demonstrate the feasibility and potential of retention index information in comprehensive 2D-GC.