Results 221 to 230 of about 64,971 (268)

Asymmetric synthesis of 2-substituted cyclic amines

Tetrahedron Letters, 2014
Cyanomethylenetributylphosphorane-mediated ring closure for the asymmetric synthesis of 2-substituted cyclic amines such as azetidines, pyrrolidines and a piperidine is reported. The desired stereochemistry at the 2-position was fixed using (S)-tert-butyl sulfinamide as a chiral auxiliary.
Amit A. Kudale, Prasad Anaspure, Falguni Goswami, Matthew Voss   +3 more
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Skeletal remodelling of α-substituted cyclic eneformamides to α-ketonyl cyclic amines

New Journal of Chemistry, 2020
A modular dehomologation strategy, which skeletally remodels cyclic α-substituted eneformamides to one-carbon shorter α-ketonyl saturated cyclic amines is described.
Timothy K. Beng, Jorge Garcia, Meagan Smith, Alexis O. Orellana   +3 more
openaire   +2 more sources

N-substituted cyclic esters of phosphoramidous acid

Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1952
1. It has been found that cyclic esters, of phosphorochloridous acid: react with aliphatic and aromatic amines, forming N-substituted cyclic esters of phosphoramidous acid. 2. The following compounds have been synthesized-and some of their properties have been studied. i.e. p.720 © 1953 Consultants Bureau.
Arbuzov A., Zoroastrova V.
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Conversion of Lactones into Substituted Cyclic Ethers

Chemistry Letters, 1989
Abstract Lactone enolates were treated with N-phenyl triflimide in the presence of hexamethylphosphoric triamide to afford smoothly the corresponding enol triflates, which, on reaction with lithium dialkylcuprates, gave rise to alkylated cyclic ethers in good yields.
Kazunori Tsushima, Katsumi Araki, Akio Murai   +2 more
openaire   +1 more source

Donor-Substituted Nitrocyclopropanes: Immediate Ring-Enlargement to Cyclic Nitronates

Organic Letters, 2013
The reaction of donor-substituted alkenes with α-diazo-α-nitro ethyl acetate under Rh catalysis was investigated; respective nitrocyclopropanes with a geminal ester functionality were generated in situ. Strong electron donors immediately led to ring-enlargement.
Christian D, Schmidt, Johannes, Kaschel, Tobias F, Schneider, Daniel, Kratzert, Dietmar, Stalke, Daniel B, Werz   +5 more
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A Convenient Synthesis of 4‐Aminoaryl Substituted Cyclic Imides.

ChemInform, 2003
AbstractFor Abstract see ChemInform Abstract in Full Text.
W MEDERSKI, M BAUMGARTH, M GERMANN, D KUX, T WEITZEL   +4 more
openaire   +1 more source

Synthetic methods for α-substituted cyclic α,β-enones

Tetrahedron, 2003
AbstractFor Abstract see ChemInform Abstract in Full Text.
Farhat Rezgui, Hassen Amri, Mohamed Moncef El Gaied   +2 more
openaire   +1 more source

Solid-Phase Synthesis of Substituted Imidazoline-Tethered 2,3-Diketopiperazines, Cyclic Ureas, and Cyclic Thioureas

Journal of Combinatorial Chemistry, 2001
Efficient methods for the solid-phase synthesis of imidazoline-tethered 2,3-diketopiperazines, cyclic ureas, and cyclic thioureas are described. Following the exhaustive reduction of resin-bound dipeptides derived from orthogonally protected diamino acids, the primary amine of the resulting tetraamines was selectively protected with Dde.
A N, Acharya, J M, Ostresh, R A, Houghten   +2 more
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Poly(cyclic imino ether)s Beyond 2‐Substituted‐2‐oxazolines

Macromolecular Rapid Communications, 2011
Abstract2‐Oxazolines (2‐OZO) are 5‐membered cyclic imino ethers whose cationic ring‐opening polymerization (CROP) mechanism and resulting polymer properties are extensively studied. However, also 6‐ and 7‐membered cyclic imino ethers can be polymerized via CROP. Together with the much less studied 4‐ and 5‐substituted main‐chain chiral poly(2‐oxazoline)
Bloksma, M.M., Schubert, U.S., Hoogenboom, R.   +2 more
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ChemInform Abstract: GEM‐DIMETHYL‐SUBSTITUTED CYCLIC ANHYDRIDES

Chemischer Informationsdienst, 1973
AbstractDurch Erhitzen der Tetramethyl‐dicarbonsäuren (I) mit Acetanhydrid lassen sich die Anhydride (IIa) bzw. (IIb) gewinnen; neben (IIa) werden auch das Dimere von (IIa) sowie höhere cyclische Analoge gebildet.
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