Tetramethylcyclopropanone and Isopropylidene(dimethyl)thiirane via Photolysis of Reluctant 3,3,5,5-Tetramethyl-1-pyrazolines; Influence of Solvent and Temperature on the Competition between [3+2]- and [4+1]-Photocycloelimination

✍ Scribed by Prof. Dr. Helmut Quasit; Dipl.-Chem. Andreas Fuss

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 245 KB
• Volume: 20
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.198102911

✦ Synopsis

In contrast, refluxing (2) and (3) (1 : 1 molar ratio) in dry ethanol gives the bznuclear complex

which on the basis of detailed 3 i P [ 'Hj -NMR studies (Fig. 2) is assigned structure (9). Related complexes of platinum(1) of type [Pt(PR,)R,PS], have recently been synthesized from [Pt(PPh,),] either by reaction with (3)IS1 or [R~PSIZI~].

A possible rationalization of the mode of formation of compounds ( 7), (8) and (9), involving oxidative addition of (3) to (2) and subsequent reductive elimination of RzNCSzH (which readily decomposes to R2NH and CS,['l), is outlined in Scheme 1.

Finally, preliminary studies show that analogous complexes can be formed starting from (2) and PF,(S)H and also, as for compounds of type ( I ) , their thio-analogues ( 7) and (8) will react with both Lewis acids and transition metal ions.