Chemicals list & Research Gallery

Cyclopropane
CAS number: 75-19-4
Cyclopropane is the cycloalkane with the molecular formula (CH2)3, consisting of three methylene groups (CH2) linked to each other to form a triangular ring. Because of its strained ring structure, it is more reactive and explosive than other saturated hydrocarbons. It was discovered by A. Freund in 1881; the same year he proposed the correct structure and synthesized it by treating 1,3-dibromopropane with sodium. For a while, cyclopropane was used as an anesthetic, but this use has been discontinued because the gas is dangerous to manufacture and handle.
Generation of Cyclopropanes 64a−c at Low Temperature
Generation of Cyclopropanes 64a−c at Low Temperature
tert-Butanol
CAS number: 75-65-0
Tert-Butanol, also known as tert-butyl alcohol or t-butanol, is a tertiary alcohol appears as a colorless, crystalline solid or liquid (depending on temperature) with a camphor-like odor and is moderately soluble in water.
Synthesis of nucleoside borane conjugates by “chemical ligation” of nucleoside borane acceptors and borane donors: 17–24. i) 2, 5, or 6, CuSO4·5H2O/potassium ascorbate, tert-butyl alcohol/water 1:1; ii) 7 or 8, CuSO4·5H2O/potassium ascorbate, tert-butyl alcohol/water 1:1
Synthesis of nucleoside borane conjugates by “chemical ligation” of nucleoside borane acceptors and borane donors: 17–24. i) 2, 5, or 6, CuSO4·5H2O/potassium ascorbate, tert-butyl alcohol/water 1:1; ii) 7 or 8, CuSO4·5H2O/potassium ascorbate, tert-butyl alcohol/water 1:1
Methanesulfonic acid
CAS number: 75-75-2
Methanesulfonic acid is an alkanesulfonic acid in which the alkyl group directly linked to the sulfo functionality is methyl. Methanesulfonic acid with high acidity is not only the catalyst in the process of chitin acylation, but also is a good solvent for partially acylated chitin.
Synthesis of liquid crystals 1–4: (i) 3,4,5-tridodecyloxybenzyl chloride, K2CO3, DMF; (ii) 4-bromoanisole, Mg, THF; (iii) phenol, methanesulfonic acid; (iv) BBr3, CH2Cl2.
Synthesis of liquid crystals 1–4: (i) 3,4,5-tridodecyloxybenzyl chloride, K2CO3, DMF; (ii) 4-bromoanisole, Mg, THF; (iii) phenol, methanesulfonic acid; (iv) BBr3, CH2Cl2.
Synthesis of the liquid crystal 8: (i) 4-bromoanisole, Mg, THF; (ii) phenol, methanesulfonic acid; (iii) CH3I, K2CO3, DMF; (iv) 1,4-phenyldiboronic acid, Pd(PPh3)4, Na2CO3, THF, H2O; (v) BBr3, CH2Cl2; (vi) 3,4,5-tridodecyloxybenzyl chloride, K2CO3, DMF.
Synthesis of the liquid crystal 8: (i) 4-bromoanisole, Mg, THF; (ii) phenol, methanesulfonic acid; (iii) CH3I, K2CO3, DMF; (iv) 1,4-phenyldiboronic acid, Pd(PPh3)4, Na2CO3, THF, H2O; (v) BBr3, CH2Cl2; (vi) 3,4,5-tridodecyloxybenzyl chloride, K2CO3, DMF.
First, the aryl triazene is converted to the corresponding aryl diazonium salt with the help of methanesulfonic acid. Then, the generated aryl diazonium salt undergoes oxidative addition with Pd(0) to obtain an aryl palladium complex, which, after coordination and insertion of a CO molecule, gives an acyl palladium intermediate. The terminal alkyne is then generated, and a new Pd-C bond is formed with the help of MeSO3−, which gives the desired alkynone after reductive elimination and provides Pd(0) for the next catalytic cycle. In this process, methanesulfonic acid may play three roles: (1) the aryl triazene generates an aryl diazonium salt; (2) MeSO3 deprotonates the terminal alkyne and re-forms methanesulfonic acid; (3) the regenerated methanesulfonic acid reacts with the previously released free amine, avoiding the nucleophilic attack of the amine on the acyl palladium intermediate and generating the non-target amide.
First, the aryl triazene is converted to the corresponding aryl diazonium salt with the help of methanesulfonic acid. Then, the generated aryl diazonium salt undergoes oxidative addition with Pd(0) to obtain an aryl palladium complex, which, after coordination and insertion of a CO molecule, gives an acyl palladium intermediate. The terminal alkyne is then generated, and a new Pd-C bond is formed with the help of MeSO3−, which gives the desired alkynone after reductive elimination and provides Pd(0) for the next catalytic cycle. In this process, methanesulfonic acid may play three roles: (1) the aryl triazene generates an aryl diazonium salt; (2) MeSO3 deprotonates the terminal alkyne and re-forms methanesulfonic acid; (3) the regenerated methanesulfonic acid reacts with the previously released free amine, avoiding the nucleophilic attack of the amine on the acyl palladium intermediate and generating the non-target amide.
2-Aminonicotinaldehyde
CAS number: 7521-41-7
2-Aminonicotinaldehyde is a biochemical reagent that can be used as a biological material or organic compound for life science related research.
Reagents and conditions: (a) LHMDS, THF, -78 °C to rt, 20%; (b) 2-aminonicotinaldehyde or 2-aminobenzaldehyde, KOH, EtOH, reflux, 47%. (c) ethylsulfonylethene, TEA, MeOH, reflux; (d) 4-fluoro-3-trifluoromethylphenylacetic acid, EDC, HOBt, NMM, DMF, rt, 80–90% two steps. (e) Pd(PPh3)4, CuI, NaCN, MeCN, microwave, 120 °C, 80–90%. Enantiomerically pure products were isolated by chiral phase HPLC.
Reagents and conditions: (a) LHMDS, THF, -78 °C to rt, 20%; (b) 2-aminonicotinaldehyde or 2-aminobenzaldehyde, KOH, EtOH, reflux, 47%. (c) ethylsulfonylethene, TEA, MeOH, reflux; (d) 4-fluoro-3-trifluoromethylphenylacetic acid, EDC, HOBt, NMM, DMF, rt, 80–90% two steps. (e) Pd(PPh3)4, CuI, NaCN, MeCN, microwave, 120 °C, 80–90%. Enantiomerically pure products were isolated by chiral phase HPLC.
L-Prolinamide
CAS number: 7531-52-4
L-Prolinamide is a tripeptide component of thyrotropin-releasing hormone that plays a role in promoting secretion of TSH and prolactin in specific cells, and is also involved in modulatory neuropeptide functions in the central nervous system.
l-Prolinamide organocatalysts.
l-Prolinamide organocatalysts.
meta-Topolin
CAS number: 75737-38-1
Meta-topolin (mT) is a relatively new cytokinin isolated from poplar leaves in 1975 and is closely related to 6-benzyladenine (BA).
Comparison of the perception of THP and THF substituted 6-(3-hydroxybenzylamino)purine (meta-topolin, mT) and mT by selected cytokinin receptors. The effect of 6-(3-hydroxybenzylamino)-9-tetrahydropyran-2-ylpurine (6(3OHBA)9THPP) and 6-(3-hydroxybenzylamino)-9-tetrahydrofuran-2-ylpurine (6(3OHBA)9THFP) on the sensing of mT by the cytokinin receptors CRE1/AHK4 (A) and AHK3 (B). trans-Zeatin (tZ) was used as the positive control.
Comparison of the perception of THP and THF substituted 6-(3-hydroxybenzylamino)purine (meta-topolin, mT) and mT by selected cytokinin receptors. The effect of 6-(3-hydroxybenzylamino)-9-tetrahydropyran-2-ylpurine (6(3OHBA)9THPP) and 6-(3-hydroxybenzylamino)-9-tetrahydrofuran-2-ylpurine (6(3OHBA)9THFP) on the sensing of mT by the cytokinin receptors CRE1/AHK4 (A) and AHK3 (B). trans-Zeatin (tZ) was used as the positive control.
beta-Cyclodextrin
CAS number: 7585-39-9
Beta-cyclodextrin is a cyclodextrin composed of seven alpha-(1->4) linked D-glucopyranose units.
Benzylated β-cyclodextrin-aldehyde and its reaction with organometallic reagents. This leads to two stereoisomers with rather different polarity.
Benzylated β-cyclodextrin-aldehyde and its reaction with organometallic reagents. This leads to two stereoisomers with rather different polarity.
TLC plate showing the different polarities of diastereoisomers 6A,D-di-C-allyl-substituted nonadecaned-O-benzylated β-cyclodextrin in pentane/ethyl acetate 4:1 eluent (left). The figure shows how steric hindrance of the subsequent glucose residue prevents the C-6 substituent from entering the tg conformation, thus forcing each diastereomer to adopt the conformer shown (right).
TLC plate showing the different polarities of diastereoisomers 6A,D-di-C-allyl-substituted nonadecaned-O-benzylated β-cyclodextrin in pentane/ethyl acetate 4:1 eluent (left). The figure shows how steric hindrance of the subsequent glucose residue prevents the C-6 substituent from entering the tg conformation, thus forcing each diastereomer to adopt the conformer shown (right).
Two reference monosaccharide derivatives 5a and 5b were prepared to determine the stereochemistry at the C-6 position. The major isomer 5b obtained by addition of (4-fluorophenyl)magnesium bromide to glucose-6-aldehyde 4 was converted to the benzylidene derivative 6. This compound has a small J5,6 and only conforms to the S-stereochemistry. The β-cyclodextrin derivative 2f was hydrolyzed and converted to the methyl glycoside to give the minor R-isomer 5a.
Two reference monosaccharide derivatives 5a and 5b were prepared to determine the stereochemistry at the C-6 position. The major isomer 5b obtained by addition of (4-fluorophenyl)magnesium bromide to glucose-6-aldehyde 4 was converted to the benzylidene derivative 6. This compound has a small J5,6 and only conforms to the S-stereochemistry. The β-cyclodextrin derivative 2f was hydrolyzed and converted to the methyl glycoside to give the minor R-isomer 5a.
Oxidation of secondary alcohols to the β-cyclodextrin ketone 4, 7e and 7f followed by reaction with organometallic reagents to give tertiary alcohols.
Oxidation of secondary alcohols to the β-cyclodextrin ketone 4, 7e and 7f followed by reaction with organometallic reagents to give tertiary alcohols.
Trifluoroacetic acid
CAS number: 76-05-1
Trifluoroacetic acid is a monocarboxylic acid that is the trifluoro derivative of acetic acid. It has a role as a reagent and a human xenobiotic metabolite.
Synthesis of 6c. Mes: 2,4,6-trimethylphenyl, TFA: trifluoroacetic acid.
Synthesis of 6c. Mes: 2,4,6-trimethylphenyl, TFA: trifluoroacetic acid.
Synthesis of β-LEAP. DIPEA=N,N’-diisopropylethylamine, NMM=4-methylmorpholine, HATU=O-(7-azabenzotriazol-1-yl)-N,N,N’,N’-tetramethyluronium hexafluorophosphate, TEA=triethylamine, TFA=trifluoroacetic acid.
Synthesis of β-LEAP. DIPEA=N,N’-diisopropylethylamine, NMM=4-methylmorpholine, HATU=O-(7-azabenzotriazol-1-yl)-N,N,N’,N’-tetramethyluronium hexafluorophosphate, TEA=triethylamine, TFA=trifluoroacetic acid.
Iodine-mediated oxidation of ynamides (Boc = tert-butoxycarbonyl, TFA = trifluoroacetic acid).
Iodine-mediated oxidation of ynamides (Boc = tert-butoxycarbonyl, TFA = trifluoroacetic acid).
Perchloric acid
CAS number: 7601-90-3
Perchloric acid is a strong acid used for complete digestions of organic material. It is normally supplied in bottles of up to one gallon in capacity at 70-72% strength. In many respects, its hazards are similar to those of nitric acid, as both are strong oxidants.
FT-IR spectra of silica-supported perchloric acid (A), perchlorate anion (B), and SiO2 (C).
FT-IR spectra of silica-supported perchloric acid (A), perchlorate anion (B), and SiO2 (C).
Silica
CAS number: 7631-86-9
Silica is another name for the chemical compound composed of silicon and oxygen with the chemical formula SiO2, or silicon dioxide.
We prepared the perchlorate salt of (S)-3 by alkylation of (S)-R-methylthio-2-(p-tolylsulfinyl)toluene 1 with MeI in the presence of silver perchlorate. 7b The resulting salt (S)-3 was quantitatively isolated by simply filtering the crude reaction mixture through a pad of celite, followed by washing with CH2Cl2 and evaporation to dryness15 (Scheme 2).
We prepared the perchlorate salt of (S)-3 by alkylation of (S)-R-methylthio-2-(p-tolylsulfinyl)toluene 1 with MeI in the presence of silver perchlorate. 7b The resulting salt (S)-3 was quantitatively isolated by simply filtering the crude reaction mixture through a pad of celite, followed by washing with CH2Cl2 and evaporation to dryness15 (Scheme 2).
Catalyst-armed Silica- and Co/C magnetic nanoparticles.
Catalyst-armed Silica- and Co/C magnetic nanoparticles.
Specular X-ray diffraction data of the OTS-covered Si/SiO2 substrate and of thin films of 2 deposited at different substrate temperatures.
Specular X-ray diffraction data of the OTS-covered Si/SiO2 substrate and of thin films of 2 deposited at different substrate temperatures.