98934-49-7Relevant academic research and scientific papers
Synthesis and Synthetic Utilization of α-Functionalized Vinylphosphonates Bearing β-Oxy or β-Thio Substituents
Kouno, Ryoji,Okauchi, Tatsuo,Nakamura, Mitsuharu,Ichikawa, Junji,Minami, Toru
, p. 6239 - 6246 (2007/10/03)
The β-hetero-substituted vinylphosphonates la-c on treatment with LDA or LTMP were readily lithiated at the α-position of the phosphono group, and the resulting α-lithiovinylphosphonates were trapped with various electrophiles to afford the corresponding α-functionalized vinylphosphonates 2-14 in 55-96% yields. The Friedel-Crafts reaction of α-(silyl)- or a-(germyl)-phosphonoketene dithioacetals 2, 9, or 4 with acid chlorides gave α-acylated phosphonoketene dithioacetals 15-19 in 53-91% yields. The palladium-catalyzed cross-coupling reaction of β-ethoxy-α-(tributylstannyl)vinylphosphonate 13 with a variety of organic halides (R = acyl, allyl, aryl, etc.) provided β-ethoxy-α-substituted vinylphosphonates 21-26 in good to moderate yields. The palladium-mediated cross-coupling reaction of α-(iodo)vinylphosphonates 7 and 14 with terminal acetylenes afforded α-alkynylated vinylphosphonates 41-44 in 69-83% yields. Several α-functionalized β-hetero-substituted vinylphosphonates were applied to the synthesis of pyrazoles and an isoxazole possessing a phosphono function.
DIALKYL FORMYL-1 METHYLPHOSPHONATES α-FONCTIONNELS-II. PREPARATION PAR VOIE THERMIQUE ET TRANSFORMATION EN HETEROCYCLES α-PHOSPHONIQUES
Aboujaoude, Elie Elia,Collignon, Noel,Savignac, Philippe
, p. 427 - 434 (2007/10/02)
The thermal condensation of functional phosphonates bearing strongly withdrawing groups (RO)2P(O)CH2Z 1 with dimethylformamide dimethyl acetal gives corresponding β-functional, β-phosphonic enamines (RO)2P(O)C(Z)=CHNMe2 2.Acid or basic hydrolysis of the enamines frequently gives the free aldehyde (RO)2P(O)CH(Z)-CHO 3.We show that the enamines can be used with success for the synthesis of heterocycles like, pyrazoles 4, pyrimidines 5, benzodiazepine 6 or indole 7, all of them substituted with a phosphonate group.
