956101-46-5Relevant academic research and scientific papers
Iridium-catalyzed asymmetric allylic substitutions with bulky amines/oxidative double bond cleavage - Entry into the reetz synthesis of amino alcohols
Seehafer, Kai,Malakar, Chandi C.,Bender, Markus,Qu, Jianping,Liang, Chen,Helmchen, Günter
, p. 493 - 501 (2016/02/18)
Branched allylic amines were prepared by Ir-catalyzed enantioselective allylic aminations with the bulky N-nucleophiles HN(Boc)2 and HNBn2. The products were transformed into N-protected amino aldehydes, which were either reduced or coupled diastereoselectively with organometallic compounds to give vicinal amino alcohols. A formal synthesis of the neurokinin receptor antagonist (+)-L-733060 was carried out as an application. Ir-catalyzed enantioselective allylic aminations with bulky N-nucleophiles HN(Boc)2 and HNBn2 gave N-protected allylic amines, which were transformed into N-protected chiral amino aldehydes. These are useful chiral building blocks as previously demonstrated by Reetz et al. A formal synthesis of the neurokinin receptor antagonist (+)-L-733060 was carried out as an application.
Enantioselective syntheses of 2,5-disubstituted pyrrolidines based on iridium-catalyzed allylic aminations-total syntheses of alkaloids from amphibian skins
Gaertner, Martin,Weihofen, Robert,Helmchen, Guenter
experimental part, p. 7605 - 7622 (2011/08/05)
A broadly applicable route to trans-2,5-disubstituted pyrrolidines has been developed. Key steps are an asymmetric iridium-catalyzed allylic amination, a Suzuki-Miyaura coupling, and an intramolecular aza-Michael addition. Enantiomeric excesses in the range of 93-99 % ee have been achieved. Total syntheses of the alkaloids (-)-225 C, (+)- and (-)-223 H (xenovenine), (+)-223 AB, (+)-195 B, and (+)-223 R have been carried out as applications. Copyright
Direct, intermodular, enantioselective, iridium-catalyzed allylation of carbamates to form carbamate-protected, branched allylic amines
Weix, Daniel J.,Markovic, Dean,Ueda, Mitsuhiro,Hartwig, John F.
supporting information; experimental part, p. 2944 - 2947 (2009/12/05)
The direct reaction between carbamates and achiral allylic carbonates to form branched, conveniently protected primary allylic amines with high regioseiectivity and enantioselectivity Is reported. This process occurs without base or with 0.5 equiv K3PO4 In the presence of a metalacyclic iridium catalyst containing a labile ethylene ligand. The reactions of aryl-, heteroaryl-, and alkyl-substituted allylic carbonates with BocNH 2, FmocNH2, CbZNH2, TrocNH2, TeocNH2, and 2-oxazolidinone occur In good yields, with high selectivity for the branched isomer and high enantioselectivities (98% average ee).
Iridium(I)-catalyzed regio- and enantioselective allylic amidation
Singh, Om V.,Han, Hyunsoo
, p. 7094 - 7098 (2008/03/11)
Ir(I)-catalyzed intermolecular allylic amidation of ethyl allyl carbonates with soft nitrogen nucleophiles under completely 'salt-free' conditions is described. A combination of [Ir(COD)Cl]2, a chiral phosphoramidite ligand L*, and DBU as a base in THF effects the reaction. The reaction appears to be quite general, accommodating a wide variety of R-groups and soft nitrogen nucleophiles, and proceeds with excellent regio- and enantioselectivities to afford the branched N-protected allylic amines. The developed reaction was conveniently utilized in the asymmetric synthesis of N-Boc protected α- and β-amino acids as well as (-)-cytoxazone.
A Concise Enantioselective Synthesis of Allylamines and N-Boc-β-Amino Acids
Alcon, Montserrat,Canas, Marc,Poch, Marta,Moyano, Albert,Pericas, Miquel A.,Riera, Antoni
, p. 1589 - 1592 (2007/10/02)
A new and efficient enantioselective synthesis of allylamines and N-Boc-β-amino acids has been developed.Starting from enantiomerically enriched N-diphenylmethyl-3-amino-1,2-diols, allylamines are easily obtained by a Corey-Hopkins deoxygenative protocol.After a change in the nitrogen protecting group, the resulting N-Boc allylamines are converted into β-amino acids by hydroboration with 9-BBN followed by oxidation with PDC in DMF.
