Complexes of Alkoxy(dialkylamino)carbenes and Hg2+ Obtained from Dicarbamoylmercury Compounds

✍ Scribed by Prof. Dr. U. Schöllkopf; Dipl.-Chem. F. Gerhart

• Publisher: John Wiley and Sons
• Year: 1967
• Tongue: English
• Weight: 229 KB
• Volume: 6
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.196705602

✦ Synopsis

7-position and 2.01 -L 0.02 protons in the 4-position, as determined from the NMR spetrum, i.e. the deuterium content of the 7-position is 0.73 j, 0.05 atom and that of the 4-position is 0.00 j, 0.05 atom. Mechanism (a), as proposed by Wittig et al. is thus confirmed by the observation that product (3), or (3'), is formed in yields greater than 73 %.

The methylene NMR resonances of (3) at -4.26 and -4.07 ppm with respect to tetramethylsilane (in CSp) were assigned by comparison with the NMR spectrum of (3) containing deuterium in the 4-position only. [4-D]-(3) was prepared by metalation of(3)with phenyl-lithium @roved by Wittiget al. [I] to occur exclusively at the 4-position) followed by quenching with heavy water. Had mechanisms (b) or (c) been operative, N-phenyl ring deuterium would have been incorporated into the 4-position, and loss of label due to metalation would have occured. This would have yielded product (3") with significantly lower deuterium content than that of the labeled starting material. Intervention of a benzocyclobutene, formed by a Stevens rearrangement of ( I ) in mechanism (a) and subsequently opening to (2), is considered unlikely because of the known stability of I-aminobenzocyclobutene [2.31. Further experiments to trap the intermediate (2) are underway.