92172-54-8

Upstream product

• 530-48-3 1,1-Diphenylethylene 
• 14160-11-3 2-methyl-3-thioxo-2,3-dihydro-1H-isoindol-1-one 
• 525-06-4 diphenyl ketene 
• 94794-63-5 C₂₃H₁₉NOS 
• 103723-96-2 2-methyl-3,'3'-diphenyl-2,3-dihydro-1H-isoindole-3-spiro-2'-thietane-1,4-dione. 

Relevant academic research and scientific papers

PHOTOREACTIONS OF PHTHALIMIDE-THIETANES: FISSION OF THE THIETANE RING AND FORMATION OF 1,2-DITHIANES

Photolysis of N-methylmonothiophthalimide (1) in the presence of thietane (4) gave 1,2-dithiane (5) and 1,3-dithiane (6).The formation of 1,2-dithianes in the photoreaction of 1 with styrene derivatives (2) is explained in terms of the intermediacy of the phthalimide-thietanes.Photolysis of the thietane ring is also described.

Photochemical Cycloaddition Reactions of N-Methyl(thiophthalimide) and N-Methyl(dithiophthalimide) with Alkenes

Irradiation of N-methyl(thiophthalimide) with alkenes leads to reaction at the thiocarbonyl, rather than at the carbonyl, group of the thioimide.Products isolated include (2+2) cycloadducts (isoindole-1-spiro-2'-thietanes), a cleavage product (a 3-alkylideneisoindol-1-one) derived from such cycloadducts, or (2+2+2) cycloadducts incorporating two molecules of thioimide (1,4-dithiane-2,3-bis-spiroisoindoles).The products are consistent with a mechanism that involves an intermediate 1,4-biradical, and they contrast markedly with those obtained from N-methylphthalimide with alkenes. N-Methyl-(dithiophthalimide) is less effective in photoreactions with alkenes, and in only one instance was a cycloadduct formed at a reasonable rate and isolated; possible reasons for this difference are discussed.

Photochemical Cycloaddition of Thiocarbonyl Compounds to Diphenylketene and a Related Ketenimine

Diphenylketene undergoes photocycloaddition with N-methylthiophthalimide, N-methyldithiophthalimide or xanthene-9-thione, to give a spiro-adduct containing a thietan-2-one ring.The photoproducts from the thioimide substrates are themselves photolabile, eliminating COS to form an alkene.Diphenyl-N-(p-tolyl)ketenimine gives analogous 2-iminothietanes on irradiation with the thioimides.

Photochemistry of Phthalimides with Olefins. Solvent-Incorporated Addition vs. Cycloaddition to Imide C(=O)-N Bond Accompanying Ring Enlargement

The photoreactions of phthalimides 1a-c and a variety of olefins (2a-g) have been investigated.Irradiation of methanol solutions of 1a in the presence of electron-rich olefins 2a-f leads to formation of methanol-incorporated adducts 3a + 4a, 9a,b, 19, 29a,b, 30a,b, and 31.Irradiation of acetonitrile solutions of 1a in the presence of relatively electron-poor aliphatic olefins 2f,g gives ring enlarged cycloddition products 23, 32, and 34, probably by a mechanism which involves collapse of an exciplex.Photolyses of 1a and 2a in less polar alcohols afford the two typesof products, simultaneously.With decrease of the solvent polarity, the yields of the solvent-incorporated adducts decrease and that of the ring-enlarged cycloaddition products increase.Irradiation of 1a and 2c leads to formation of the other types of products: in methanol 20 is obtained together with 19, and in acetonitrile 22 and 24 are formed together with 23.The formation of 24 is rationalized by a mechanism in which degradation of an oxetane (27) is involved.The products 20 and 22 appear to be derived through electron transfer from 2c to the excited state of 1a.Phenanthrene (electron-transfer) sensitization of the reaction 1a + 2c gives 20 and 23 in methanol and 22 in acetonitrile, selectively.These results and ΔG values associated with the electron transfer support an electron-transfer mechanism for the solvent-incorporated adduct formation.

PHOTOCYCLOADDITION REACTIONS OF N-METHYLTHIOPHTHALIMIDE

N-Methylthiophthalimide undergoes a photochemical cycloaddition reaction with 2,3-dimethylbut-2-ene or with stilbene to give products containing a spiro-thietane system; with 1,1-diphenylethene the product isolated is a diphenylmethyleneisoindoline.