Flooding Performance and Optimization of Injection Parameters of Nanosized Oil Displacement Agents in Extra-Low-Permeability Reservoirs.

There have been few studies on the role of nanofluids in oil displacement and injection parameters, despite their significant impact on the oil displacement effect. To enhance oil recovery in an ultralow-permeability reservoir, the nanosized oil-displacement agent with nano-SiO2 modified by a silane coupling agent as a main component was selected for the first time in the Changqing oilfield. To assess the performance of the nanofluid, various factors such as particle size, contact angle, interfacial tension, and emulsion stability were taken into consideration. The oil displacement effect of nanofluids was evaluated by a microscopic model and ultralow-permeability core displacement experiment, and its optimal injection parameters were determined. The average particle size of the nano-oil displacement agent is 22-30 nm. It can change the wetting condition of the rock from oil-wet to water-wet and reduce the oil-water interfacial tension. Even at 80 °C, the emulsion formed by the agent remained stable. The oil displacement experiment shows that the nano-oil displacement agent whose injection pressure increases can displace the residual oil trapped in small pores that cannot be affected by conventional water flooding. The injection mode of "nanoflooding agent drive + water drive + nanoflooding agent drive", injection rate of 0.1 mL/min, injection concentration of 0.5%, and injection volume of 0.5 PV (0.25 PV per segment), which can effectively guide the injection of the oil displacement agent, achieve the best oil displacement effect.

A high-efficiency gene silencing in plants using two-hit asymmetrical artificial MicroRNAs.

MicroRNAs (miRNAs) are small non-coding RNA molecules that play a crucial role in gene regulation. They are produced through an enzyme-guided process called dicing and have an asymmetrical structure with two nucleotide overhangs at the 3' ends. Artificial microRNAs (amiRNAs or amiRs) are designed to mimic the structure of miRNAs and can be used to silence specific genes of interest. Traditionally, amiRNAs are designed based on an endogenous miRNA precursor with certain mismatches at specific positions to increase their efficiency. In this study, the authors modified the highly expressed miR168a in Arabidopsis thaliana by replacing the single miR168 stem-loop/duplex with tandem asymmetrical amiRNA duplexes that follow the statistical rules of miRNA secondary structures. These tandem amiRNA duplexes, called "two-hit" amiRNAs, were shown to have a higher efficiency in silencing GFP and endogenous PDS reporter genes compared to traditional "one-hit" amiRNAs. The authors also demonstrated the effectiveness of "two-hit" amiRNAs in silencing genes involved in miRNA, tasiRNA, and hormone signalling pathways, individually or in families. Importantly, "two-hit" amiRNAs were also able to over-express endogenous miRNAs for their functions. The authors compare "two-hit" amiRNA technology with CRISPR/Cas9 and provide a web-based amiRNA designer for easy design and wide application in plants and even animals.

Design, Synthesis and Characterization of Palladium-Functionalized Covalent Organic Framework and Its Application as Heterogeneous Catalysis for C-H Arylation of Azoles.

A novel triazine-based covalent organic framework (TFPT-Bz COF) has been constructed by the condensation of 2,4,6-tris(5-formyl-2-pyridinoxy)-1,3,5-triazine (TFPT) and benzidine (BZ) with deep eutectic solvent (DES) as the reaction medium. After the introduction of Pd ions through strong coordination to TFPT-Bz COF matrix, the constructed TFPT-Bz COF/Pd composite exhibited excellent catalytic activity for C-H arylation of azoles with aryl halides in 2-methyltetrahydrofuran. The protocol allows the arylation of a variety of substituted azoles with diverse aryl halides in high to excellent yield. Moreover, the TFPT-Bz COF/Pd catalyst can be recycled several times without significantly reducing its activity.

The DEAD-box helicase RCF1 plays roles in miRNA biogenesis and RNA splicing in Arabidopsis.

RCF1 is a highly conserved DEAD-box RNA helicase found in yeast, plants, and mammals. Studies about the functions of RCF1 in plants are limited. Here, we uncovered the functions of RCF1 in Arabidopsis thaliana as a player in pri-miRNA processing and splicing, as well as in pre-mRNA splicing. A mutant with miRNA biogenesis defects was isolated, and the defect was traced to a recessive point mutation in RCF1 (rcf1-4). We show that RCF1 promotes D-body formation and facilitates the interaction between pri-miRNAs and HYL1. Finally, we show that intron-containing pri-miRNAs and pre-mRNAs exhibit a global splicing defect in rcf1-4. Together, this work uncovers roles for RCF1 in miRNA biogenesis and RNA splicing in Arabidopsis.

Integrating BSA-Seq with RNA-Seq Reveals a Novel Fasciated Ear5 Mutant in Maize.

Increasing grain yield is required to meet the rapidly expanding demands for food, feed, and fuel. Inflorescence meristems are central to plant growth and development. However, the question concerning whether inflorescence development can be regulated to improve grain yield remains unclear. Here, we describe a naturally occurring single recessive mutation called fea5 that can increase grain yield in maize. Using bulk segregant analysis sequencing (BSA-seq), the candidate region was initially mapped to a large region on chromosome 4 (4.68 Mb-11.26 Mb). Transcriptome sequencing (RNA-seq) revealed a total of 1246 differentially expressed genes (DEGs), of which 835 were up-regulated and 411 were down-regulated. Further analysis revealed the enrichment of DEGs in phytohormone signal transduction. Consistently, phytohormone profiling indicated that auxin (IAA), jasmonic acid (JA), ethylene (ETH), and cytokinin (CK) levels increased significantly, whereas the gibberellin (GA) level decreased significantly in fea5. By integrating BSA-seq with RNA-seq, we identified Zm00001d048841 as the most likely candidate gene. Our results provide valuable insight into this new germplasm resource and the molecular mechanism underlying fasciated ears that produce a higher kernel row number in maize.

Suppression of microRNA168 enhances salt tolerance in rice (Oryza sativa L.).

BACKGROUND: Rice is a salt-sensitive crop. Complex gene regulatory cascades are likely involved in salinity stress in rice roots. microRNA168 (miR168) is a conserved miRNA among different plant species. It in-directly regulates the expression of all miRNAs by targeting gene ARGONAUTE1(AGO1). Short Tandem Target Mimic (STTM) technology is an ideal approach to study miRNA functions by in-activating mature miRNA in plants. RESULTS: In this study, rice miR168 was inactivated by STTM. The T3 generation seedlings of STTM168 exhibited significantly enhanced salt resistance. Direct target genes of rice miR168 were obtained by in silico prediction and further confirmed by degradome-sequencing. PINHEAD (OsAGO1), which was previously suggested to be a plant abiotic stress response regulator. RNA-Seq was performed in root samples of 150mM salt-treated STTM168 and control seedlings. Among these screened 481 differentially expressed genes within STTM168 and the control, 44 abiotic stress response related genes showed significant difference, including four known salt-responsive genes. CONCLUSION: Based on sequencing and qRT-PCR, a "miR168-AGO1-downstream" gene regulation model was proposed to be responsible for rice salt stress response. The present study proved miR168-AGO1 cascade to play important role in rice salinity stress responding, as well as to be applied in agronomic improvement in further.

Dissecting the Regulatory Network of Maize Phase Change in ZmEPC1 Mutant by Transcriptome Analysis.

The developmental phase changes of maize are closely associated with the life span, environmental adaption, plant height, and disease resistance of the plant and eventually determines the grain yield and quality of maize. A natural mutant, Early Phase Change 1 (ZmEPC1), was selected from the inbred line KN5585. Compared with the wild type plant, the ZmEPC1 mutant exhibits deceased plant stature, accelerated developmental stages, and decreased leaf size. Through the transcriptome sequencing analysis of leaf samples at flowering stage, a total of 4583 differentially expressed genes (DEGs) were screened between the mutant and wild type, including 2914 down-regulated genes and 1669 up-regulated genes. The GO enrichment and KEGG enrichment analysis revealed that the DEGs were mainly involved in hormone response, hormone signal transduction, autophagy, JA response and signal response, photosynthesis, biotic/abiotic stress, and circadian rhythms. The RT-qPCR results revealed that the most tested DEGs display consistent expression alterations between V5 and FT stages. However, several genes showed opposite expression alterations. Strikingly, most of the JA biosynthesis and signaling pathway-related genes displayed diametrically expression alterations between V5 and FT stages. miR156, a key regulator of plant phase transition, exhibited significant down-regulated expression at V5 and FT stages. The expression of two miR156 target genes were both significantly different between mutants and wild type. In conclusion, ZmEPC1 was identified to be mainly involved in the regulation of JA-mediated signaling pathways and hormone response and signaling, which is possible to confer developmental phase change through miR156-SPLs pathway.

Alagille syndrome associated with total anomalous pulmonary venous connection and severe xanthomas: A case report.

BACKGROUND: Alagille syndrome (ALGS) is an autosomal dominant genetic disorder caused by mutations in the JAG1 or NOTCH2 gene. It is characterized by decreased intrahepatic bile ducts associated with a variety of abnormalities in many other organ systems, such as the cardiovascular, skeletal, and urinary systems. CASE SUMMARY: We report a rare case of ALGS. A 1-month-old male infant presented with sustained jaundice and had a rare congenital heart disease: Total anomalous pulmonary venous connection (TAPVC). Sustained jaundice, particularly with cardiac murmur, caught our attention. Laboratory tests revealed elevated levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, total bilirubin, and total bile acids, indicating serious intrahepatic cholestasis. Imaging confirmed the presence of butterfly vertebra at the seventh thoracic vertebra. This suggested ALGS, which was confirmed by genetic testing with a c.3197dupC mutation in the JAG1 gene. Ursodiol was administered immediately after confirmation of the diagnosis, and cardiac surgery was performed when the patient was 1.5 month old. He recovered well after treatment and was discharged at the age of 3 mo. At the age of two years, the patient returned to our clinic because multiple cutaneous nodules with xanthomas appeared, and their size and number increased over time. CONCLUSION: We report a unique case of ALGS associated with TAPVC and severe xanthomas. This study has enriched the clinical manifestations of ALGS and emphasized the association between JAG1 gene and TAPVC.

[Clinical characteristics and analysis of IDS gene variant in a child with mucopolysaccharidosis type â ¡].

OBJECTIVE: To summarize the clinical features, laboratory examination and genetic analysis of a patient with mucopolysaccharidosis type Ⅱ (MPS Ⅱ). METHODS: Clinical manifestations, results of urine glycosaminoglycans (GAGs) and dermatan sulfate assay, metabolites related to MPS in peripheral blood leukocytes were analyzed. Meanwhile, the child and his mother were subjected to next-generation sequencing and Sanger sequencing. RESULTS: The boy has presented with global development delay, coarse facies, frequent upper-respiratory infections, hearing loss, indirect inguinal hernia, hepatosplenomegaly, and skeletal deformities. His urine GAGs were significantly elevated, and the urinary dermatan sulfate (DS) was positive. Meanwhile, the activity of idose-2-sulfatase was extremely reduced. The patient was found to harbor a hemizygote c.676C>G (p. His226Asp) missense variant in exon 5 of IDS gene, for which his mother was heterozygous. CONCLUSION: The novel c.676C>G variant of the IDS gene probably underlay the MPS Ⅱ in this child. Genetic testing combined with enzymatic analysis can enable effective diagnosis and classification of MPS.

Uncovering the Gene Regulatory Network of Maize Hybrid ZD309 under Heat Stress by Transcriptomic and Metabolomic Analysis.

Maize is an important cereal crop but is sensitive to heat stress, which significantly restricts its grain yield. To explore the molecular mechanism of maize heat tolerance, a heat-tolerant hybrid ZD309 and its parental lines (H39_1 and M189) were subjected to heat stress, followed by transcriptomic and metabolomic analyses. After six-day-heat treatment, the growth of ZD309 and its parental lines were suppressed, showing dwarf stature and rolled leaf compared with the control plants. ZD309 exhibited vigorous growth; however, M189 displayed superior heat tolerance. By transcriptomic and metabolomic analysis, hundreds to thousands of differentially expressed genes (DEGs) and metabolites (DEMs) were identified. Notably, the female parent H39 shares more DEGs and DEMs with the hybrid ZD309, indicating more genetic gain derived from the female instead of the male. A total of 299 heat shock genes detected among three genotypes were greatly aggregated in sugar transmembrane transporter activity, plasma membrane, photosynthesis, protein processing in the endoplasmic reticulum, cysteine, and methionine metabolism. A total of 150 heat-responsive metabolites detected among three genotypes were highly accumulated, including jasmonic acid, amino acids, sugar, flavonoids, coumarin, and organic acids. Integrating transcriptomic and metabolomic assays revealed that plant hormone signal transduction, cysteine, and methionine metabolism, and α-linolenic acid metabolism play crucial roles in heat tolerance in maize. Our research will be facilitated to identify essential heat tolerance genes in maize, thereby contributing to breeding heat resistance maize varieties.

Histone H3K4me3 modification is a transgenerational epigenetic signal for lipid metabolism in Caenorhabditis elegans.

As a major risk factor to human health, obesity presents a massive burden to people and society. Interestingly, the obese status of parents can cause progeny's lipid accumulation through epigenetic inheritance in multiple species. To date, many questions remain as to how lipid accumulation leads to signals that are transmitted across generations. In this study, we establish a nematode model of C. elegans raised on a high-fat diet (HFD) that leads to measurable lipid accumulation, which can transmit the lipid accumulation signal to their multigenerational progeny. Using this model, we find that transcription factors DAF-16/FOXO and SBP-1/SREBP, nuclear receptors NHR-49 and NHR-80, and delta-9 desaturases (fat-5, fat-6, and fat-7) are required for transgenerational lipid accumulation. Additionally, histone H3K4 trimethylation (H3K4me3) marks lipid metabolism genes and increases their transcription response to multigenerational obesogenic effects. In summary, this study establishes an interaction between a network of lipid metabolic genes and chromatin modifications, which work together to achieve transgenerational epigenetic inheritance of obesogenic effects.

Lack of Association of FLT3 rs2504235 and Absence of SLITRK1 var321 in Patients with Tic Disorders from Guangdong Province, China.

OBJECTIVE: Tic disorders (TDs) are highly polygenic and heritable neurodevelopmental disorders characterized by the presence of movements (motor tics) and/or vocalizations (phonic tics). SLITRK1 is a pathogenic variation of TD, and in a recent genome-wide association study in those of European ancestry, a single-nucleotide polymorphism (rs2504235) in the FLT3 gene was significantly associated with TDs/Tourette's syndrome. However, these results need to be proved in different populations. This study aimed to determine whether these two genetic variants were also associated with TD patients in south China. METHODS: A total of 116 child TD patients and 114 healthy controls were included. All children underwent peripheral blood sampling for genomic DNA extraction. Gene fragments with two single-nucleotide polymorphisms were amplified by PCR and sequenced by Sanger chain termination before genotype analysis. RESULTS: SLITRK1 var321 was not observed in any of the TD patients or controls. No significant difference was observed in allelic frequencies or genotypic distributions of rs2504235 between TD patients and controls. CONCLUSION: Our results provide no evidence to support the previous conclusion that SLITRK1 var321 plays a major role in TDs, and FLT3 rs2504235 was not significantly associated with TDs in our cohort.

Physical and neuropsychological development of children with Citrin deficiency. / Citrinç¼ºé™·ç— æ‚£å„¿ä½“æ ¼å’Œç¥žç»å¿ƒç†å‘è‚²çŠ¶å†µ.

OBJECTIVES: To study the physical and neuropsychological development of children with Citrin deficiency (CD). METHODS: A total of 93 children, aged 1.9-59.8 months, who were diagnosed with CD by SLC25A13 gene analysis in the First Affiliated Hospital of Jinan University from August 2010 to August 2015, were enrolled as subjects. A retrospective analysis was performed for their birth condition and physical growth and neuropsychological development indices. Among these children, 7 underwent physical measurement and neuropsychological development assessment within 1 year old and after 1 year old, and therefore, a total of 100 cases were included for analysis. RESULTS: For the 93 children with CD, the incidence rate of failure to thrive was 25% (23 children) and the proportion of small for gestational age was 47% (44 children). For the 100 cases of CD, the incidence rates of growth retardation, underweight, emaciation, overweight, and microcephalus were 23% (23 cases), 14% (14 cases), 4% (4 cases), 8% (8 cases), and 9% (9 cases), respectively. The incidence rate of neuropsychological developmental delay was 25% (25 cases), and the incidence rates of development delay in the five domains of adaptability, gross motor, fine motor, language, and social ability were 7% (7 cases), 15% (15 cases), 7% (7 cases), 9% (9 cases), and 7% (7 cases), respectively. CONCLUSIONS: Physical and neuropsychological developmental delay can be observed in children with CD, and physical and neuropsychological development should be regularly assessed.

Molecular epidemiologic study of citrin deficiency by screening for four reported pathogenic SLC25A13 variants in the Shaanxi and Guangdong provinces, China.

BACKGROUND: Citrin deficiency (CD) is an autosomal recessive disease resulting from biallelic mutations of the SLC25A13 gene. This study aimed to investigate the molecular epidemiological features of CD in the Guangdong and Shaanxi provinces of China. METHODS: A total of 3,409 peripheral blood samples from Guangdong and 2,746 such samples from Shaanxi province were collected. Four prevalent SLC25A13 mutations NG_012247.2 (NM_014251.3): c.852_855del, c.1638_1660dup, c.615+5G>A, and c.1751-5_1751-4ins(2684) were screened by using the conventional polymerase chain reaction (PCR)/PCR-restriction fragment length polymorphism and newly-developed multiplex PCR methods, respectively. The mutated SLC25A13 allele frequencies, carrier frequencies, and CD morbidity rates were calculated and then compared with the Chi-square and Fisher's exact tests. RESULTS: The mutations were detected in 68 out of 6,818 SLC25A13 alleles in Guangdong and 29 out of 5,492 alleles in the Shaanxi population. The carrier frequencies were subsequently calculated to be 1/51 and 1/95, while the CD morbidity rates were 1/10,053 and 1/35,865, in the 2 populations, respectively. When compared with the Shaanxi population, Guangdong exhibited a higher frequency of mutated SLC25A13 allele (68/6,818 vs. 29/5,492, χ2=8.570, P=0.003) in general, with higher c.852_855del (54/6,818 vs. 13/5,492, χ2=17.328, P=0.000) but lower c.1751-5_1751 -4ins(2684) (2/6,818 vs. 9/5,492, P=0.015) allele frequencies. The distribution of c.615+5G>A and c.1638_1660dup between the 2 provinces, as well as all 4 prevalent mutations among different geographic regions within the 2 provinces, did not differed significantly. CONCLUSIONS: Our findings depicted the CD molecular epidemiological features in Guangdong and Shaanxi populations, providing preliminary but significant laboratory evidences for the subsequent CD diagnosis and management in the 2 provinces of mainland China.

Incorporation of exome-based CNV analysis makes trio-WES a more powerful tool for clinical diagnosis in neurodevelopmental disorders: A retrospective study.

Neurodevelopmental disorders (NDDs) are a genetically heterogeneous group of diseases, affecting 1%-3% of children. Whole-exome sequencing (WES) has been widely used as a first-tier tool for identifying genetic causes of rare diseases. Trio-WES was performed in a cohort of 74 pedigrees with NDDs. Exome-based copy number variant (CNV) calling was incorporated into the traditional single-nucleotide variant (SNV) and small insertion/deletion (Indel) analysis pipeline for WES data. An overall positive diagnostic yield of 54.05% (40/74) was obtained in the pipeline of combinational SNV/Indel and CNV analysis, including 35.13% (26/74) from SNV/Indel analysis and 18.92% (14/74) from exome-based CNV analysis, respectively. In total, SNV/Indel analysis identified 38 variants in 28 different genes, of which 24 variants were novel; exome-based CNV analysis identified 14 CNVs, including 2 duplications and 12 deletions, which ranged from 440 bp (single exon) to 16.86 Mb (large fragment) in size. In particular, a hemizygous deletion of exon 1 in the SLC16A2 gene was detected. Based on the diagnostic results, two families underwent prenatal diagnosis and had unaffected babies. The incorporation of exome-based CNV detection into conventional SNV/Indel analysis for a single trio-WES test significantly improved the diagnostic rate, making WES a more powerful, practical, and cost-effective tool in the clinical diagnosis of NDDs.

MiR319-targeted OsTCP21 and OsGAmyb regulate tillering and grain yield in rice.

Multiple genes and microRNAs (miRNAs) improve grain yield by promoting tillering. MiR319s are known to regulate several aspects of plant development; however, whether miR319s are essential for tillering regulation remains unclear. Here, we report that miR319 is highly expressed in the basal part of rice plant at different development stages. The miR319 knockdown line Short Tandem Target Mimic 319 (STTM319) showed higher tiller bud length in seedlings under low nitrogen (N) condition and higher tiller bud number under high N condition compared with the miR319a-overexpression line. Through targets prediction, we identified OsTCP21 and OsGAmyb as downstream targets of miR319. Moreover, OsTCP21 and OsGAmyb overexpression lines and STTM319 had increased tiller bud length and biomass, whereas both were decreased in OsTCP21 and OsGAmyb knockout lines and OE319a. These data suggest that miR319 regulates rice tiller bud development and tillering through targeting OsTCP21 and OsGAmyb. Notably, the tiller number and grain yield increased in STTM319 and overexpression lines of OsTCP21 and OsGAmyb but decreased in OE319a and knockout lines of OsTCP21 and OsGAmyb. Taken together, our findings indicate that miR319s negatively affect tiller number and grain yield by targeting OsTCP21 and OsGAmyb, revealing a novel function for miR319 in rice.

A terbium(III) lanthanide-organic framework as a selective and sensitive iodide/bromide sensor in aqueous medium.

A potent luminescent sensor for the detection of iodide ions was developed based on a terbium(iii)-based lanthanide-organic framework [Tb(cpia)(H2O)2]n·nH2O (1), which was prepared under hydrothermal conditions using the 5-(4-carboxyphenoxy)isophthalic acid (H3cpia) bridging ligand. Compound 1 exhibits superior luminescence quenching behavior towards I- with high sensitivity and selectivity among various anions and shows real-time response. Moreover, the mechanism of the selective luminescence quenching response for I- can be mainly explained by the absorption competition between 1 and I-. According to this quenching mechanism, we find that compound 1 can also detect Br- by adjusting the excitation wavelength. Significantly, this work could serve as a general guidance for the design and synthesis of pollutant sensors.

Neonatal Intrahepatic Cholestasis caused by Citrin Deficiency: In vivo and in vitro studies of the aberrant transcription arising from two novel splice-site variants in SLC25A13.

Neonatal Intrahepatic Cholestasis caused by Citrin Deficiency (NICCD) is an autosomal recessive disease resulting from biallelic SLC25A13 mutations, and its diagnosis relies on genetic analysis. This study aimed to characterize the pathogenicity of 2 novel splice-site variants of SLC25A13 gene. Two patients (C0476 and C0556) suspected to have NICCD, their family members and 9 healthy volunteers were recruited as the research subjects. The SLC25A13 genotypes NG_012247.2(NM_014251.3): c.[852_855del]; [69+5G > A] in patient C0476 and c.[1453-1G > A]; [1751-5_1751-4ins (2684)] in patient C0556 were identified by means of polymerase chain reaction, long and accurate polymerase chain reaction, as well as Sanger sequencing. The 2 splice-site variants were absent in control databases and predicted to be pathogenic by computational analysis. The alternative splice variants in monocyte-derived macrophages from patient C0476 demonstrated exon 2 skipping [r.16_69del; p.(Val6_Lys23del)] in vivo, while minigene analysis revealed both exon 2-skipping and retained products from c.69+5G > A in vitro. In the patient C0556, an aberrant transcript [r.1453del; p.(Gly485Valfs*22)] resulting from c.1453-1G > A was detected on minigene splicing study. Thus, c.69+5G > A and c.1453-1G > A were both proved to be pathogenic. The 2 novel splice-site variants expanded the SLC25A13 mutation spectrum and provided reliable molecular markers for the definite diagnosis and genetic counseling of NICCD in the affected families.

Visible-Light-Mediated Oxidative Amidation of Aldehydes by Using Magnetic CdS Quantum Dots as a Photocatalyst.

A magnetic CdS quantum dot (Fe3 O4 /polydopamine (PDA)/CdS) was synthesized through a facile and convenient method from inexpensive starting materials. Characterization of the prepared catalyst was performed by means of FTIR spectroscopy, XRD, SEM, TEM, energy-dispersive X-ray spectroscopy, and vibrating-sample magnetometer techniques. Fe3 O4 /PDA/CdS was found to be a highly active photocatalyst for the amidation of aromatic aldehydes by using air as a clean oxidant under mild conditions. The photocatalyst can be recovered by magnetic separation and successfully reused for five cycles without considerable loss of its catalytic activity.

Catalyst-free Synthesis of Aminomethylphenol Derivatives in Cyclopentyl Methyl Ether via Petasis Borono-Mannich Reaction.

OBJECTIVE: Aminomethylphenol molecules have wider applications in pharmaceuticals, agrochemicals, plant protection and promising functional materials. The development of an efficient and practical method to prepare this class of compound is highly desirable from both environmental and economical points of view. MATERIALS AND METHODS: In order to establish an effective synthetic method for preparing aminomethylphenol derivatives, the Petasis borono-Mannich reaction of salicylaldehyde, phenylboronic acid and 1,2,3,4- tetrahydroisoquinoline was selected as a model reaction. A variety of reaction conditions are investigated, including solvent and temperature. The generality and limitation of the established method were also evaluated. RESULTS AND DISCUSSION: It was found that model reaction can be carried out in cyclopentyl methyl ether at 80 oC under catalyst-free conditions. This protocol, with broad substrate applicability, the reaction of various arylboronic acid, secondary amine and salicylaldehyde proceeded smoothly under optimal reaction conditions to afford various aminomethylphenol derivatives in high yields. A practical, scalable, and high-yielding synthesis of aminomethylphenol derivatives was successfully accomplished. CONCLUSION: A catalyst-free practical method for the synthesis of minomethylphenol derivatives based on Petasis borono-Mannich (PBM) reaction of various arylboronic acid, secondary amine and salicylaldehyde in cyclopentyl methyl ether has been developed. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvents, use of cyclopentyl methyl ether as the reaction medium, clean reaction profiles, easy operation, and high to excellent yield.