Cycloaddition reactions of dialkylaminobis(trifluoromethyl)boranes with isocyanates and isothiocyanates

✍ Scribed by A. Ansorge; D.J. Brauer; H. Bürger; F. Dörrenbach; T. Hagen; G. Pawelke; W. Weuter

• Book ID: 104150414
• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 38 KB
• Volume: 54
• Category: Article
• ISSN: 0022-1139
• DOI: 10.1016/s0022-1139(00)83686-6

✦ Synopsis

The reactions of (CF3)2BNMe2 (Al) and (CF3)2BNEt2 (A2) with isocyanates and isothiocyanates have been studied. Near room temperature the C=N bonds of R-N=C=O and R-N=C=S undergo i2+2] cycloaddition with the B-N bond of Al to yield the four-membered rings 8. I, V, VI, VIII and IX rearrange at -6O'C to form the isomers C. At room temperature A2 reacts with Me-N=C=O to yield directly X. Both X and XI incorporate reversibly Me-N=C-0 to form the six-membered heterocycles D. The structures of II, VII, XIV and XVII were established by single-crystal X-ray diffraction methods. The other structural assignments are based on mass spectrometry and vibrational and multinuclear NMR spectra.