A medium fluorous Grubbs–Hoveyda 2nd generation catalyst for phase transfer catalysis of ring closing metathesis reactions
摘要:
A fluorous Grubbs-Hoveyda metathesis catalyst supported on Teflon (R) powder, that readily moves between the solid phase (Teflon (R)) and the liquid phase (DMF) was prepared. By modulating the hydrophobicity of the reaction medium at the end of the reaction, the supported catalyst could be recovered by simple filtration even though the catalyst existed in a homogeneous state during the reaction. In RCM reactions, the catalyst could be reused up to three times with only a slight loss in reactivity with each subsequent cycle. (C) 2015 Elsevier Ltd. All rights reserved.
A Facile Preparation of N-(Isopropoxyalkyl) Amides by Generation and Trapping of N-Acyliminium Ions from Ionization-Rearrangement Reactions of N-Triflyloxy Amides
摘要:
A series of hydroxamic acids were converted to N-triflyloxy amides which were heated in 2-propanol to give N-(1-isopropoxyalkyl) amides in high yields. The method is simple, direct, and extremely tolerant of structural diversity both in the N-acyl group, as well as in the 1-isopropoxyalkyl group. N-Alkylation of secondary N-(1-isopropoxyalkyl) amides can be used for converting them to tertiary N-(1-isopropoxyalkyl) amides. N-Acyliminium ions of wide structural diversity can be generated easily from N-(1-isopropoxyalkyl) amides available by this methodology.
A Facile Preparation of N-(Isopropoxyalkyl) Amides by Generation and Trapping of N-Acyliminium Ions from Ionization-Rearrangement Reactions of N-Triflyloxy Amides
作者:Robert V. Hoffman、Naresh K. Nayyar
DOI:10.1021/jo00092a007
日期:1994.7
A series of hydroxamic acids were converted to N-triflyloxy amides which were heated in 2-propanol to give N-(1-isopropoxyalkyl) amides in high yields. The method is simple, direct, and extremely tolerant of structural diversity both in the N-acyl group, as well as in the 1-isopropoxyalkyl group. N-Alkylation of secondary N-(1-isopropoxyalkyl) amides can be used for converting them to tertiary N-(1-isopropoxyalkyl) amides. N-Acyliminium ions of wide structural diversity can be generated easily from N-(1-isopropoxyalkyl) amides available by this methodology.
A medium fluorous Grubbs–Hoveyda 2nd generation catalyst for phase transfer catalysis of ring closing metathesis reactions
A fluorous Grubbs-Hoveyda metathesis catalyst supported on Teflon (R) powder, that readily moves between the solid phase (Teflon (R)) and the liquid phase (DMF) was prepared. By modulating the hydrophobicity of the reaction medium at the end of the reaction, the supported catalyst could be recovered by simple filtration even though the catalyst existed in a homogeneous state during the reaction. In RCM reactions, the catalyst could be reused up to three times with only a slight loss in reactivity with each subsequent cycle. (C) 2015 Elsevier Ltd. All rights reserved.