ISSN:
0947-3440
Keywords:
Phosphonate-substituted allylic carbonates
;
Allylic alkylation, palladium(0)-catalyzed
;
Glycine equivalents
;
Regioselectivity
;
Stereoselectivity
;
Alkylations
;
Palladium
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Palladium(0)-catalyzed allylic alkylation of diethyl (acetyl-amino)malonate (6), ethyl (diphenylmethyleneamino)acetate (7), and (diphenylmethyleneamino)acetonitrile (8), respectively, with the acrolein-derived 1-dialkoxyphosphinyl-substituted carbonates 5 provides the γ-substituted vinylphosphonates 9-11 in very good yields and with high regioselectivity. The stereochemical outcome is dependent on the mode of nucleophilic activation of the glycine equivalents 6-8: When the reactions are performed in the presence of N,O-bis(trimethylsilyl)acetamide (BSA) the (Z) isomers (Z)-9-(Z)-11 are highly favoured, while in the absence of any additional activation of the nucleophiles the corresponding (E) isomers predominate. In the latter case, upon alkylation of the Schiff base derivatives 7 and 8, up to 30% of the α-substitution products 12 and 13, respectively, are isolated as by-products. The vinylphosphonates 9-11 are easily converted to the racemic 2-amino-5-phosphono-4-pentenoic acids (Z)-3 and (E)-3, and to the saturated analogue 1.
Additional Material:
5 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.199719970722
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