Phenylcarbonyl isothiocyanate

Heating of the cycloadduct derived from 4-nitrophenyl isothiocyanate and dicyclohexyl-carbodiimide causes cycloreversion to give the starting materials In the reaction of phenylcarbonyl isothiocyanate and substituted phenylcarbonyl isothiocyanates, respectively, with carbodiimides, [2-1-4] cycloadducts 221 are usually obtained, but the [2 + 2] cycloadduct 220 is also formed when the reaction of DCC with phenylth-iocarbonyl isothiocyanate is stopped at shorter reaction times. ... 

Cycloaddition Reactions. In [2+2] cycloaddition reactions with car-bodiimides sometimes [2+4] cycloadducts are produced as coproducts. Examples include the reaction of phenylcarbonyl isocyanate, phenylcarbonyl isothiocyanate and thiocarbamoyl isothiocyanate with carbodiimides to give [2+4] cycloadducts, discussed in Section 5.3.1. In the current section, mainly [2+4] cycloaddition of carbodiimides as dienophile with dienes derived from oxoketenes, generated in situ or masked oxoketenes, especially 2,3-diones investigated by Kollenz and his coworkers are discussed. 

Morpholinocyclohexene reacts with phenylcarbonyl isothiocyanate to give the benzoxazine-4-thione derivative 33, via a [4+2] cycloaddition process . 

Phenylcarbonyl isothiocyanate reacts with 1-azirines to give [2+2] cycloadducts 51 however, the strained bicyclic adduct undergoes rearrangement to give 4,5-disubstituted 2-benzamido-l,3-thiazoles 52". ... 

The reaction of l,2X -azaphospholes 69 with methyl isothiocyanate proceeds across the C=N bond of the isothiocyanate to give the [2+2] cycloadduct 70. In contrast, phenyl isothiocyanate, Me2P(S)NCS, Ph2P(S)NCS and phenylcarbonyl isothiocyanate react across their C=S bond to give the isomeric [2+2] cycloadducts 71. ... 

Cyclohexyl-2(2 -thienyl)-3-benzoylaziridine also reacts with aryl isothiocyanates to give [3-1-2] cycloadducts The reaction of A -tosylaziridines with isothiocyanates in the presence of tributylphosphine affords the [3+2] cycloadducts in yields up to 78 Phenylcarbonyl isothiocyanates react with 1,3-dipoles 99, generated in the treatment of 4-substituted 1,2,3-thiadiazoles with KOH/EtOH, to give the heterocycle 100 . 

Similar [3+2] cycloaddition products are obtained in the reaction of 104 with 4-nitrophenyl isothiocyanate and phenylcarbonyl isothiocyanate. 

The reaction of diazaazoles 143 with phenylcarbonyl isothiocyanate affords the [3-1-2] cycloadducts 144 24. 

The addition of phenylcarbonyl isothiocyanate to a variety of dienes to give the 1,2,3,6-tetrahydropyridine derivatives 177 occurs at room temperature over a period of 6 to 7 months - not exactly a click reaction... 

Some monosubstituted acetone hydrazones 190 react with phenylcarbonyl isothiocyanate to give the oxatriazepine derivatives 191... 

Cycloadditions The [4+2] cycloaddition reactions of carbodiimides with phenyl-carbonyl isocyanate, phenylcarbonyl isothiocyanate and thiocarbamoyl isothiocyanate have been discussed above. In the dimerization reactions the functional carbodiimides react as both the diene and the dienophile. Unsaturated carbodiimides, generated in situ, can be trapped with N=N bond- or C=N bond-containing substrates. 

The [2+2] cycloaddition reaction of isothiocyanates with ketenimines proceeds at room temperature across the C=S bond of the isothiocyanates and the C=C bond of the ketenimines to give 2,4-bis(imino)thietanes. However, only reactive isothiocyanates, such as arenesulfonyl isothiocyanates (48-54 % yield) or phenylcarbonyl isothiocyanate (44 % yield), undergo this reaction... 

Nitrones undergo the [3+2] cycloaddition reaction mainly across the C=N bond of the isothiocyanate. For example, C-phenyl-N-methylnitrone 109 reacts with phenyl isoth-iocyanate " and phenylcarbonyl isothiocyanateto give l,2,4-oxadiazolidine-5-thiones 110. 

Cyclic aldo- and ketonitrones react similarly with phenyl isothiocyanateHowever, substituted phenyl isothiocyanates react with 5,5-dimethyl-l-pyrroline-l-oxide to give cycloadducts derived from addition across the C=N bond as well as the C=S bond of the isothiocyanates. The C=S cycloadducts are unstable and undergo further transformations . The [3+2] cycloaddition reaction of 3,3,5,5-tetramethylpyrroline-l-oxide with aryl- and phenylcarbonyl isocyanates also occurs exclusively by addition across the C=S bond . ... 

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See also in sourсe #XX -- [ ]

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