5622-72-0Relevant articles and documents
Pd(II)-catalyzed allylic C-H amination for the preparation of 1,2- and 1,3-cyclic ureas
Nishikawa, Yasuhiro,Kimura, Seikou,Kato, Yuri,Yamazaki, Natsuka,Hara, Osamu
supporting information, p. 888 - 891 (2015/03/18)
A general synthesis of 1,2- and 1,3-cyclic ureas is accomplished by intramolecular allylic C-H amination employing Pd(TFA)2/bis-sulfoxide as a catalyst. By careful modification of substrates and catalyst, a variety of 1,2-cyclic ureas are accessible from not previously employed terminal olefins substituted in allylic or vinylic positions. Furthermore, MS4A is found to be an effective additive for the synthesis of 1,3-cyclic ureas in good yields and excellent diastereoselectivities.
Diastereoselective synthesis of 2,5-disubstituted decahydroquinolines via ring-rearrangement metathesis and zirconium-mediated cyclization
Neidhoefer, Juergen,Blechert, Siegfried
, p. 3047 - 3054 (2007/10/03)
A diastereoselective approach to 2,5-substituted decahydroquinolines by zirconium-mediated cyclization of unsaturated α,α′- disubstituted piperidines II is described. The required piperidines could be obtained from secondary sulfonamides III via ruthenium-catalyzed ring-rearrangement metathesis (RRM) in high yields. Racemic trans-195A and 2-epi-trans-195A were synthesized in 8 steps starting with butyraldehyde and cyclohex-2-enol.
Chiral oxime ethers in asymmetric synthesis. Part 5. Asymmetric synthesis of 2-substituted 5- to 8-membered nitrogen heterocycles by oxime addition-ring-closing metathesis
Hunt, James C. A.,Laurent, Pierre,Moody, Christopher J.
, p. 2378 - 2389 (2007/10/03)
Addition of organometallic reagents to chiral oxime ethers 1 derived from an unsaturated aldehyde, or addition of an alkene containing organometallic to chiral aldoxime ethers 2 results in highly stereoselective formation of the hydroxylamines 6. N-Allylation gives the dienes 7 which undergo ring-closing metathesis (RCM) reaction to give the 5-, 6-, and 7-membered nitrogen heterocycles 8. Likewise, the benzyl carbamates 9, also prepared by stereoselective addition to oxime ethers, were converted into dienes 10, which underwent RCM to give the 5- to 8-membered azacycles 11. The oxime addition-RCM protocol is thus a versatile method for the asymmetric synthesis of nitrogen heterocycles, further exemplified by the conversion of the unsaturated heterocycles into chiral piperidines, including the alkaloid (-)-coniine.
Stereocontrolled synthesis of homoallylic amines using phosphine oxides and isoxazolines
Armstrong, Susan K.,Warren, Stuart,Collington, Eric W.,Naylor, Alan
, p. 4171 - 4174 (2007/10/02)
Allylic diphenylphosphine oxides (7) undergo stereo selective 1,3-dipolar cycloadditions with nitrile oxides to give Δ2-isoxazolines (8). These may be reduced, also stereoselectively, to δ-amino-β-hydroxyalkyldiphenylphosphine oxides (9). Stereospecific Wittig-Horner type elimination of Ph2PO2-from amino alcohols (9) gives homoallylic amines (10) with controlled double bond geometry.
