690274-99-8Relevant articles and documents
Practical Procedures for the Preparation of N-tert-Butyldimethylsilylhydrazones and Their Use in Modified Wolff-Kishner Reductions and in the Synthesis of Vinyl Halides and gem-Dihalides
Furrow, Michael E.,Myers, Andrew G.
, p. 5436 - 5445 (2007/10/03)
In this work we develop practical chemistry for the preparation of N-tert-butyldimethylsilylhydrazone (TBSH) derivatives from carbonyl-containing compounds and show that these products serve as superior alternatives to simple hydrazones in Wolff-Kishner-type reduction reactions, in the Barton vinyl iodide preparation, in the synthesis of vinyl bromides, and in the synthesis of gem-diiodides, gem-dibromides, and gem-dichlorides. In our new procedure for silyl hydrazone synthesis, aliphatic and aromatic ketones and aldehydes are shown to undergo highly efficient coupling (typically >95% yield) to form the corresponding TBSH derivatives when combined with equimolar amounts of 1,2-bis(tert-butyldimethylsilyl)-hydrazine (BTBSH) and a catalytic quantity of scandium trifluoromethanesulfonate (typically, 0.01 mol %), neat, or in solvent. Optimized procedures are provided for the use of TBSH derivatives in a Wolff-Kishner-type reduction protocol that proceeds at low temperature (23-100 °C) and in a single reaction flask. Similarly, protocols for the use of TBSH derivatives as precursors to vinyl halides and gem-dihalides are described in detail.
