15780-23-1Relevant articles and documents
METAL-ASSISTED REACTIONS-12. UNUSUAL SELECTIVITY IN THE REDUCTION OF KETONES WITH ZINC OR CADMIUM BIS-TETRAHYDROBORATE/DIMETHYLFORMAMIDE COMPLEX
Hussey, Brendan J.,Johnstone, Robert A. W.,Boehm, Peter,Entwistle, Ian D.
, p. 3769 - 3774 (1982)
Zinc bis-tetrahydroborate forms a solid complex with dimethylformamide (DMF) of composition, Zn(BH4)2*1.5DMF.Unlike zinc bis-tetrahydroborate itself, the complex with DMF can be stored as a solid at room temperature.Ketones and aldehydes are reduced to the corresponding alcohols by the complex but the mechanism of reduction appears to be different from that using zinc bis-tetrahydroborate itself and from other tetrahydroborates in that only one hydride equivalent from each BH4- unit is utilized and not four.Further, although saturated aliphatic ketones are reduced rapidly to alcohols, aromatic ketones react much more slowly and α,β-unsaturated ketones react very slowly so that the complex appears to have selective reducing potential with regard to different classes of ketones.It is also apparent that the zinc bis-tetrahydroborate/DMF complex reduces sterically hindered saturated ketones much more slowly than it does unhindered ketones.An analogous cadmium bis-tetrahydroborate/DMF complex can be prepared in solution and reacts with ketones similarly to the zinc complex.
