- Synthesis of N?H Bearing Imidazolidinones and Dihydroimidazolones Using Aza-Heck Cyclizations
-
The synthesis of unsaturated, unprotected imidazolidinones via an aza-Heck reaction is described. This palladium-catalyzed process allows for the cyclization of N-phenoxy ureas onto pendant alkenes. The reaction has broad functional group tolerance, can b
- Xu, Feiyang,Shuler, Scott A.,Watson, Donald A.
-
p. 12081 - 12085
(2018/09/11)
-
- A Simple, Broad-Scope Nickel(0) Precatalyst System for the Direct Amination of Allyl Alcohols
-
The preparation of allylic amines is traditionally accomplished by reactions of amines with reactive electrophiles, such as allylic halides, sulfonates, or oxyphosphonium species; such methods involve hazardous reagents, generate stoichiometric waste streams, and often suffer from side reactions (such as overalkylation). We report here the first broad-scope nickel-catalysed direct amination of allyl alcohols: An inexpensive NiII/Zn couple enables the allylation of primary, secondary, and electron-deficient amines without the need for glove-box techniques. Under mild conditions, primary and secondary aliphatic amines react smoothly with a range of allyl alcohols, giving secondary and tertiary amines efficiently. This “totally catalytic” method can also be applied to electron-deficient nitrogen nucleophiles; the practicality of the process was demonstrated in an efficient, gram-scale preparation of the calcium antagonist drug substance flunarizine (Sibelium).
- Sweeney, Joseph B.,Ball, Anthony K.,Lawrence, Philippa A.,Sinclair, Mackenzie C.,Smith, Luke J.
-
supporting information
p. 10202 - 10206
(2018/08/06)
-
- Benign catalysis with iron: Unique selectivity in catalytic isomerization reactions of olefins
-
The use of noble metal catalysts in homogeneous catalysis has been well established. Due to their price and limited availability, there is growing interest in the substitution of such precious metal complexes with readily available and bio-relevant catalysts. In particular, iron is a "rising star" in catalysis. Herein, we present a general and selective iron-catalyzed monoisomerization of olefins, which allows for the selective generation of 2-olefins. Typically, common metal complexes give mixtures of various internal olefins. Both bulk-scale terminal olefins and functionalized terminal olefins give the corresponding products under mild conditions in good to excellent yields. The proposed reaction mechanism was elucidated by in situ NMR studies and supported by DFT calculations and extended X-ray absorption fine structure (EXAFS) measurements.
- Jennerjahn, Reiko,Jackstell, Ralf,Piras, Irene,Franke, Robert,Jiao, Haijun,Bauer, Matthias,Beller, Matthias
-
experimental part
p. 734 - 739
(2012/06/04)
-
- Lewis Acid Mediated [2,3]-Sigmatropic Rearrangement of Allylic α-Amino Amides
-
Boron trifluoride and BBr3 mediated [2,3]-sigmatropic rearrangements of allylic α-amino amides have been developed affording secondary amines in good yields. (E)-Crotyl and (E)-cinnamyl α-amino amides 2b and 2c exhibit excellent syn-diastereoselectivity upon rearrangement with either Lewis acid. The allylic amine 2a forms upon treatment with BF 3 or BBr3 a five-membered heterocylic complex in which a single halide anion has been displaced by the carbonyl oxygen atom. The structures of the Lewis acid-amine complexes were elucidated using NMR spectroscopy. A plausible reaction mechanism, based on DFT calculations, is presented. Thus, BF3- or BBr3-complexed allylic amines 2 are shown to preferentially proceed, after deprotonation, via an endo transition state.
- Blid, Jan,Brandt, Peter,Somfai, Peter
-
p. 3043 - 3049
(2007/10/03)
-
- Aza-[2,3] sigmatropic rearrangement of phosphoramides
-
The aza-[2,3] sigmatropic rearrangement wits realized by using a phosphoramide group as a stabilization group of the carbanion. Not only (E)-substituted alkene, but also (Z)-, and trisubstituted alkene can be used as substrates.
- Manabe, Shino
-
p. 2491 - 2492
(2007/10/03)
-
- Asymmetric allylic amination catalyzed by chiral ferrocenylphosphine-palladium complexes
-
A palladium complex bearing chiral (hydroxyalkyl)ferrocenylphosphine ligand was found to be a highly regio-and stereoselective catalyst for the asymmetric allylic animation of 2-butenyl acetates with benzylamine, the nucleophilic attack of the amine takin
- Hayashi, Tamio,Kishi, Kohei,Yamamoto, Akihiro,Ito, Yoshihiko
-
p. 1743 - 1746
(2007/10/02)
-