New Aspects in Phosphorus Chemistry II

2003
ISBN: 978-3-540-44086-4
Verlag: Springer Berlin Heidelberg

Buch, Englisch, Band 223, 263 Seiten, HC runder Rücken kaschiert, Format (B × H): 160 mm x 241 mm, Gewicht: 582 g

Reihe: Topics in Current Chemistry

Strong non-ionic bases are highly advantageous as stoichiometric reagents and as catalysts in synthetic organic chemistry owing to side reactions that f- quently occur when ionic bases such as LDA or alkali metal alkoxides are employed. A second reason that non-ionic bases are frequently more useful in these applications is that such bases are often more soluble in less polar organic solvents,particularly at low temperatures. Thirdly,non-ionic bases can provide reactive naked or tightly associated deprotonated substrate anions that are s- bilized by the relatively large,poorly solvated cations formed by the protonated base. In such cations,extensive positive charge delocalization can occur. Prior to our work on pro-azaphosphatranes of type 1 (Scheme 1),the very strong n- ionic bases utilized for organic transformations were largely confined to the nitrogenous bases shown below (Scheme 2). Scheme 1 Scheme 2 4 J. G. Verkade 2 Uses of Strong Nonionic Nitrogen Bases 2. 1 Amines One of the earliest strong non-ionic bases to make its appearance was Proton Sponge and its derivatives [1] and these systems have been reviewed [2]. More recently Proton Sponge has been used in the palladium-catalyzed arylation of 2,3-dihydrofuran [3], and it also catalyzes Knoevenagel condensations of s- strates possessing activated methylene groups [4]. Recently the synthesis of the macrocyclic tetramine below (Scheme 3) was reported [5]. The encrypted nitrogens are very basic (pK ,24.

Zielgruppe

Professional/practitioner

Autoren/Hrsg.

Majoral, Jean-Pierre

Weitere Mitwirkende

Balczewski, P.

Caminade, A.-M.

Heydt, H.

Ito, S.

Kee, T.P.

Majoral, J.-P.

Mikolajczyk, M.

Nixon, T.D.

Streubel, R.

Verkade, J.G.

Yoshifuji, M.

Fachgebiete

• Naturwissenschaften Chemie Anorganische Chemie Festkörperchemie
• Naturwissenschaften Chemie Anorganische Chemie Nichtmetallische Chemie
• Naturwissenschaften Chemie Anorganische Chemie Komplexchemie
• Naturwissenschaften Chemie Organische Chemie
• Naturwissenschaften Biowissenschaften Biochemie (nichtmedizinisch)

Inhaltsverzeichnis

P(RNCH2CH2)3N: Very Strong Non-Ionic Bases Useful in Organic Synthesis.- The Asymmetric Phospho-Aldol Reaction. Past, Present and Future.- Chemistry of Phosphanylidene Carbenoids.- Transient Nitrilium Phosphanylid Complexes — New Versatile Building Blocks in Phosphorus Chemistry.- What to do with Phosphorus in Dendrimer Chemistry.- Phosphonate Chemistry and Reagents in the Synthesis of Biologically Active and Natural Products.- The Fascinating Chemistry of 1,3,5-Triphosphinines and Valence Isomers [1].