Effect of polar substituents on hindered rotation about sulfur-nitrogen and carbonyl-nitrogen bonds in methyl N-arenesulfenyl-N-benylurethanes

✍ Scribed by Daniel Kost; Arie Zeichner

• Book ID: 104224601
• Publisher: Elsevier Science
• Year: 1975
• Tongue: French
• Weight: 266 KB
• Volume: 16
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)91466-7

✦ Synopsis

The substantial effect of polar substituents on barriers to rotation about S-N bonds in substituted arenesulfenamides, X-C6H4SWR8R", has been attributed to (p-d)n conjugation between nitrogen and sulfur.' However, no such effect has been observed on barriers to syn, anti interconversion in N-alkylidenearenesulfenamides, RR'C=NSAr, and consequently the importance of (p-d)-bonding has been questioned.* The absence of a polar substituent effect on nitrogen inversion barriers in a series of N-arenesulfenylaziridines. X-C6H4SW%(CH3)2, has been interpreted as evidence for the absence of acceleration of the rate of nitrogen inversion as a result of d-orbital conjugation.' This interpretation requires that the extent of (p-d)n bonding in the