81194-47-0Relevant academic research and scientific papers
4,5-Diisopropyl-B-[(E)-[(3'-menthofuryl)dimethylsilyl]allyl]-1,3,2-dio xaborolane, an improved chiral reagent for the anti α-hydroxyallylation of aldehydes: Application to the enantioselective synthesis of (-)-swainsonine
Hunt,Roush
, p. 1112 - 1124 (1997)
Diisopropyl tartrate-modified (E)-[γ-(furyldimethylsilyl)allyl]boronates 16 and 11 were designed for the enantioselective synthesis of substituted anti-3,4-dihydroxy-1-butenes 9 via the anti-α-hydroxyallylation of aldehydes. The reactions of aldehydes with 16 and 11 provided furyldimethylsilyl-substituted anti-1,2-silanols 12 and 13 with good enantioselectivity (74-82% ee), and the silanols were oxidized to the corresponding anti-1,2-diols 9 by a modified Fleming-Tamao oxidation protocol. The high reactivity of the (menthofuryl)silane unit toward electrophilic substitution allowed complete protodesilylation of menthofuryl-substituted silanols 13 and subsequent oxidation to diols 9 in a one-pot operation without competing protodesilylation of the allylsilane unit. However, a two-stop protocol was required for the protodesilylation-oxidation of the less reactive 2-(5-methyl)furyl-substituted silanols 12. Reagents 16 and 11 exhibited similar diastereoselectivity in double asymmetric reactions with three chiral aldehydes 23-25 (80 to >92% de, with the exception of the mismatched reactions with aldehyde 25, which were essentially unselective). However, [[[2-(5-methylfuryl)]dimethylsilyl]allyl]boronate 16 could only be synthesized in ≤15% yield, and oxidations of the 2-(5-methylfuryl)-substituted silanols 12 were lower-yielding than oxidations of the corresponding menthofuryl-substituted silanols 13. Thus, diisopropyl tartrate-modified (E)-[γ-[(menthofuryl)dimethylsilyl]allyl]boronate 11 proved to be the more useful of the two reagents. As a demonstration of the utility of 11 in the synthesis of polyhydroxylated natural products, this new reagent was used in a brief and highly stereoselective synthesis of the naturally occurring alkaloid (-)-swainsonine (42).
The study of intramolecular tandem radical cyclizations of acylsilanes with radicalphiles attached on silicon
Tang, Kuo-Hsiang,Liao, Fang-Yu,Tsai, Yeun-Min
, p. 2037 - 2045 (2007/10/03)
Radical cyclizations of acylsilanes with radicalphilic pendant introduced on silicon proceeded in a tandem fashion to give spiro products containing a cyclic silyl ether skeleton. Because the alkoxysilyl group can be replaced with a hydroxy group through
Reductive Alkylation/Arylation of Arylcarbinols and Ketones with Organosilicon Compounds
Cella, J. A.
, p. 2125 - 2130 (2007/10/02)
Arylcarbinols react with certain organosilanes in the presence of boron trifluoride to yield hydrocarbons resulting from transfer of an R group from silicon to carbon.The transfer works well with aryl- and allylsilanes and fails with alkylsilanes.Allylation of ionizable carbinols is sometimes accompanied by cation-mediated oligomerization.This can be offset by converting the carbinols in question to their respective allyldimethylsilyl ethers followed by rearrangement of the ethers with BF3.While diaryl ketones are sluggishly bisallylated, the corresponding ketals undergo smooth bisallylation at 0 deg C with allytrimethylsilane/BF3/CH2Cl2.
