128640-69-7Relevant academic research and scientific papers
REACTIONS OF 1,2-OXAPHOSPHOLENE-2-OXIDES 5. CONSEQUENCES OF REDUCTION
Mualla, Maher,Macomber, Roger S.
, p. 15 - 20 (2007/10/02)
The reactions of 5,5-dimethyl-2-phenyl-1,2-oxaphosphol-3-ene 2-oxide (1a) with a variety of reducing agents have been studied.Catalytic hydrogenation of (1a) (Pd/C) resulted in reduction of the C=C bond, giving 5,5-dimethyl-2-phenyl-1,2-oxaphospholane 2-oxide (6).By contrast, hydroboration with excess BH3-THF left the double bond intact, and reduced the P=O group.The product, 5,5-dimethyl-2-phenyl-1,2-oxaphosphol-3-ene (7), is itself unstable, but it can be isolated as the novel borano complex (8).The P=O group in (1a) can also be reduced by trichlorosilane.In this case the unstable (7) was isolated as the corresponding tungsten pentacarbonyl complex (10).Conversion of (1a) to the corresponding P-sulfide (9) was readly accomplished, but (9) could not be selectively reduced with metallic sodium.Lithium aluminium hydride reduced both the C=C bond and the P=O group, but the presumed product 5,5-dimethyl-2-phenyl-1,2-oxaphospholane (5) was unstable and underwent ring opening to a compound tentatively identified as (3-hydroxy-3-methylbutyl)phenylphosphinic acid (3), which is in equilibrium with its phosphine oxide tautomer (4).
