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A series of novel imidazole-fused carbaporphyrinoids were obtained by a surprisingly simple approach by exploiting the reaction of tosylmethylisocyanide (TOSMIC) with readily obtainable 2-aza-21-carbaporphyrins. A facile methylation of silver(III) complexes of these fused systems leads to cationic N-heterocyclic carbene precursors. [ABSTRACT FROM AUTHOR]

The 1,3-dipolar cycloaddition of nitrilimine, generated in situ from (Z)-N-aryl-2-oxopropanehydrazonoyl bromide and Et3N, to 3-arylpyrrolo[ 1,2-a]pyrazine afforded novel 1-(1,5-diaryl-1,10b-dihydropyrrolo[1,2-a][1,2,4]triazolo[3,4-c]pyrazin-3-yl)ethanones in moderate yields. The structures of all the products were characterized thoroughly by NMR, IR, and HRMS. [ABSTRACT FROM AUTHOR]

Novel 4'-aryl-1,2',5'-triphenyl-2',4',6,7-tetrahydrospiro[indazole-5,3'-pyrazol]-4(1H)-ones have been synthesized in moderate yields by 1,3-dipolar cycloaddition of 5-arylmethylidene-1-phenyl-1,5,6,7-tetrahydro-4H-indazol-4-ones and diphenylnitrilimine, generated in situ from N-phenylbenzohydrazonoyl chloride and triethylamine. According to structural analyses by NMR spectroscopy and single crystal X-ray diffraction method, the reaction proceeds regioselectively affording products with C(5)-C(3') connectivity at the spiro center. [ABSTRACT FROM AUTHOR]

The 1,3-dipolar cycloaddition of azomethine ylide, generated in situ from isatin and sarcosine, to 5-arylmethylidene-1-phenyl-6,7-dihydro-1H-indazol-4(5H)-ones afforded novel 1'-methyl-4'-aryl-1-phenyl-6,7-dihydrodispiro[indazole-5,3'-pyrrolidine-2',3"-indole]-2",4(1H,1"H)-diones in moderate yields. The structures of all the products were characterised thoroughly by NMR, IR, HRMS, together with X-ray crystallographic analysis. [ABSTRACT FROM AUTHOR]

3-Cyano-N-confused porphyrin derivatives were synthesised by the reaction of N-confused porphyrin with trimethylsilyl cyanide in the presence of tetrabutylammonium fluoride in moderate yield. The reaction took placed regioselectively in the 3-position carbon of the inverted pyrrole of N-confused porphyrins. [ABSTRACT FROM AUTHOR]

The sulfa-Michael/aldol cascade reaction of (E)-7-arylidene-6,7-dihydroindolizin-8(5H)-ones and 1,4-dithiane-2,5-diol afforded novel 2'-aryl-4'-hydroxy-4',5,5',6-tetrahydro-2'H,8H-spiro[indolizine-7,3'-thiophen]-8-ones in low to moderate yields. The structures of all products were characterized thoroughly by NMR, IR, HRMS, together with X-ray crystallographic analysis. [ABSTRACT FROM AUTHOR]

Steroidal 3,5-diene is an important structural motif in steroid drugs. In this report, an iridium-catalyzed reduction–elimination of readily available steroidal 4-en-3-ones is realized to prepare steroidal 3,5-dienes. At a low catalyst loading (S/C = 200), heating 4-en-3-ones in a water-mixed organic solvent with formic acid without inert atmosphere protection afforded the desired 3,5-dienes in moderate to excellent yields. In a gram-scale preparation, recrystallization is used instead of column chromatography to purify products. Excellent functionality tolerance and regioselectivity are featured. Structural moieties such as alkanols (primary, secondary and tertiary), esters (except for formate), tolylates, and ketones (endocyclic or exocyclic) are not affected. Surprisingly, the reduction–elimination only takes place at A-ring 4-en-3-ones. In addition, bicyclic 4-en-3-ones are also viable substrates. Synthetic applications of steroidal 3,5-dienes are demonstrated. Our method can also lead to steroidal 3,5-dienes-3-d (＞99% d-incorporation) when DCO2D and D2O are used together. [ABSTRACT FROM AUTHOR]