Activation of Fmoc-protected N,O-acetals using trimethylsilyl halides: mechanistic and synthetic studies.
Trimethylsilyl halide activation of Fmoc-protected N,O-acetals yields reactive intermediates capable of efficiently adding to a variety of enamines. NMR studies have provided evidence that a stable halomethyl carbamate intermediate forms in solution. Good yields are obtained over a broad range of enamine nucleophiles encompassing both cyclic and acyclic ketone-derived and aldehyde-derived enamines. Preliminary studies suggest that the enamine additions occur through a concerted, S(N)2-type mechanism.
Boaz
Nicholas C
NC
Department of Chemistry, Lebanon Valley College, Annville, Pennsylvania 17003, USA.
Bair
Nathaniel C
NC
Le
Thanh T
TT
Peelen
Timothy J
TJ
D000080:Acetals / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques; D005449:Fluorenes / Q000737:chemistry*; D006846:Hydrocarbons, Halogenated / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
C496789:9-fluorenylmethoxycarbonyl; D000080:Acetals; D005449:Fluorenes; D006846:Hydrocarbons, Halogenated; D014297:Trimethylsilyl Compounds