Yue-Yang Liu

[3 + 2] Cycloaddition of Oxazol-5-(4H)-ones with Nitrones for Diastereoselective Synthesis of Isoxazolidin-5-ones

In the presence of TMSCl, the [3 + 2] cycloaddition of oxazol-5-(4H)-ones with nitrones proceeded smoothly and furnished the desired isoxazolidin-5-ones with high diastereoselectivities in reasonable chemical yields. The chemical structure of the title compounds was firmly confirmed by X-ray single-crystal structure analysis.

Facile access to novel 1,2,4-oxadiazinan-5-ones via [3 + 3] cycloaddition of in situ generated azaoxyallyl cations with nitrones

In the presence of Na2CO3, azaoxyallyl cations in situ generated from α-halohydroxamates with nitrones readily underwent [3 + 3] cycloaddition, and gave rise to 1,2,4-oxadiazinan-5-one derivatives in 56–99% chemical yields. The chemical structure of the title compounds was unambiguously identified by X-ray single crystal structure analysis.

Direct access to non-aromatic 1,2,3,6-tetrahydro-1,2,3,4-tetrazines via [4 + 2] cycloaddition of α-halogeno hydrazones with azodicarboxylic acid derivatives

In the presence of K2CO3, the [4 + 2] cycloaddition of α-halogeno hydrazones with azodicarboxylic acid derivatives proceeded efficiently, and delivered novel non-aromatic 1,2,3,6-tetrahydro-1,2,3,4-tetrazines in moderate to excellent chemical yields.

1,3-Dipolar [3 + 3] cycloaddition of α-halohydroxamate-based azaoxyallyl cations with hydrazonoyl chloride-derived nitrile imines

Promoted by Et3N, the 1,3-dipolar [3 + 3] cycloaddition of α-halohydroxamate-based azaoxyallylcations with hydrazonoyl chloride-derived nitrile imines occurred efficiently, and furnished desired products in acceptable chemical yields. The chemical structure of the title compounds was firmly confirmed by an X-ray single crystal structure analysis.

Construction of 2,3,4,5-tetrahydro-1,2,4-triazines via [4 + 2] cycloaddition of α-halogeno hydrazones to imines

In the presence of sodium carbonate, the [4 + 2] cycloaddition of α-halogeno hydrazones to imines proceeded readily, and furnished 2,3,4,5-tetrahydro-1,2,4-triazines in moderate to high chemical yields.

Diastereoselective synthesis of highly functionalized polycyclic benzosultams via tandem cyclisations of cyclic N-sulfonylimines with in situ generated Huisgen 1,4-dipoles

Under mild reaction conditions, the tandem cycloadditions of cyclic N-sulfonylimines with in situ generated Huisgen 1,4-dipoles from dialkyl acetylenedicarboxylates and pyridines underwent readily, and delivered highly functionalized polycyclic 1,2,3,4-tetrahydropyrimidine-fused benzosultams in low to excellent chemical yields with excellent diastereoselectivities.