Zhen-Ting Du

Improved Synthesis of 5-Substituted 1H-Tetrazoles via the [3+2] Cycloaddition of Nitriles and Sodium Azide Catalyzed by Silica Sulfuric Acid

A silica supported sulfuric acid catalyzed [3+2] cycloaddition of nitriles and sodium azide to form 5-substituted 1H-tetrazoles is described. The protocol can provide a series of 5-substituted 1H-tetrazoles using silica sulfuric acid from nitriles and sodium azide in DMF in 72%–95% yield.

A facile demethylation of ortho substituted aryl methyl ethers promoted by AlCl 3

An efficient and practical demethylation of ortho substituted aryl methyl ethers using AlCl3 has been developed. This method gives a high conversion, is simple to operate and is cost-effective. A mechanism involving the complexation of AlCl3 with the OMe and the adjacent electron withdrawing group is proposed. Many functional groups can be tolerated in the demethylation process, and 29 examples gave a demethylated product in a yield of 90–98%.

A facile and efficient synthesis of diaryl amines or ethers under microwave irradiation at presence of KF/Al2O3 without solvent and their anti-fungal biological activities against six phytopathogens.

A series of diaryl amines, ethers and thioethers were synthesized under microwave irradiation efficiently at presence of KF/Al2O3 in 83%–96% yields without any solvent. The salient characters of this method lie in short reaction time, high yields, general applicability to substrates and simple workup procedure. At the same time, their antifungal biological activities against six phytopathogen were evaluated. Most of the compounds (3b, 3c, 3g–o) are more potent than thiophannate-methyl against to Magnaporthe oryzae. This implies that diaryl amine or ether moiety may be helpful in finding a fungicide against Magnaporthe oryzae.

A Facile Asymmetric Synthesis of (S)-14-Methyl-1-Octadecene, the Sex Pheromone of the Peach Leafminer Moth

An asymmetric synthesis of 14-methyl-1-octadecene, the sex pheromone of the peach leafminer moth has been achieved. The target molecule was synthesized in six linear steps and in 30.3% overall yield from commercially available hexanoyl chloride, (S)-4-benzyloxazolidin-2-one and 1,9-nonanediol. The hexanoyl chloride was connected with (S)-4-benzyloxazolidin-2-one, and with the induction of the chiral oxazolidinone auxiliary, after chiral methylation, LAH reduction and then tosylation gave the chiral key intermediate 5 in high stereoselectivity. 1,9-Nonanediol, was selectively brominated, THP protected and subjected to Li2CuCl4-mediated C-C coupling to afford a C12 intermediate. The target molecule, (S)-14-methyl-1-octadecene, was obtained after the two parts were subjected to a second Li2CuCl4-mediated C-C coupling. Our synthetic approach represents the first time a substrate-control asymmetric synthesis of (S)-14-methyl-1-octadecene has been reported.

An improved synthesis of 1,2-diarylethanols under conventional heating and ultrasound irradiation.

A simple and efficient synthesis of 1,2-diarylethanols has been developed. The procedure involved the reaction between a variety of toluene derivatives and aryl aldehydes under conventional heating and ultrasound irradiation. This procedure possesses several advantages such as operational simplicity, high yield, safety and environment benignancy. Ultrasound was proved to be very helpful to the reaction, markedly improving the yield and the reaction rate.

3,4-Bis(4-meth-oxy-phen-yl)-2,5-dihydro-1H-pyrrole-2,5-dione.

In the title compound, C18H15NO4, the benzene rings form quite different dihedral angles [16.07 (1) and 59.50 (1)°] with the central pyrrole ring, indicating a twisted molecule. Conjugation is indicated between the five- and six-membered rings by the lengths of the C—C bonds which link them [1.462 (3) and 1.477 (3) Å]. The most prominent feature of the crystal packing is the formation of inversion dimers via eight-membered {⋯HNCO}2 synthons.

2-Meth­oxy-4-methyl-1-[1-(phenyl­sulfon­yl)propan-2-yl]benzene

The title molecule, C17H20O3S, displays a U-shaped structure; the two benzene rings are nearly parallel and partially overlapped to each other, the dihedral angle and centroid-to-centroid distance being 15.0 (2)° and 3.723 (2) Å. In the crystal, weak intermolecular C—H⋯O hydrogen bonds link the molecules, forming supramolecular chains running along the a axis.

4-[4-(1H-Tetra-zol-5-yl)phen-oxy]benzaldehyde.

The asymmetric unit of the title compound, C14H10N4O2, contains two independent molecules with similar structures. In one molecule, the tetrazole ring is oriented at dihedral angles of 17.71 (16) and 57.13 (17)°, respectively, to the central benzene ring and the terminal benzene ring; in the other molecule, the corresponding dihedral angles are 16.46 (18) and 75.87 (18)°. Intermolecular N—H⋯N hydrogen bonds and weak C—H⋯O and C—H⋯N hydrogen bonds occur in the crystal structure.

Synthesis of the Sex Pheromone of the Tea Tussock Moth Based on a Resource Chemistry Strategy

Synthesis of the sex pheromone of the tea tussock moth in 33% overall yield over 10 steps was achieved. Moreover, the chiral pool concept was applied in the asymmetric synthesis. The synthesis used a chemical available on a large-scale from recycling of wastewater from the steroid industry. The carbon skeleton was constructed using the C4+C5+C8 strategy. Based on this strategy, the original chiral center was totally retained.

3,4-Bis[4-(4-meth-oxy-phen-oxy)phen-yl]-1-methyl-1H-pyrrole-2,5-dione.

The title compound, C31H25NO6, has a structure related to other 3,4-diaryl-substituted maleic anhydride derivatives which have been shown to be useful as photochromic materials. The dihedral angles between the maleimide ring system and the benzene rings bonded to it are 44.48 (3) and 17.89 (3)°, while the angles between each of the latter rings and the corresponding ether bridging connected methoxybenzene rings are 78.61 (8) and 72.67 (7)°. In the crystal, the molecules are linked by C—H⋯O interactions.