325490-29-7Relevant academic research and scientific papers
Chemoselective, Regioselective, and Enantioselective Allylations of NH2OH under Iridium Catalysis
Chen, Jiteng,Liang, Qingchun,Zhao, Xiaoming
, p. 5383 - 5386 (2019)
The utilization of unprotected NH2OH, which is not only an oxygen nucleophile but also a nitrogen nucleophile, in iridium-catalyzed allylic substitution is realized under mild conditions. The chemoselectivity, stereoselectivity, and multiple al
Rhodium-Catalyzed Regiodivergent Hydrothiolation of Allyl Amines and Imines
Kennemur, Jennifer L.,Kortman, Gregory D.,Hull, Kami L.
supporting information, p. 11914 - 11919 (2016/10/06)
The regiodivergent Rh-catalyzed hydrothiolation of allyl amines and imines is presented. Bidentate phosphine ligands with larger natural bite angles (βn ≥ 99°), for example, DPEphos, dpph, or L1, promote a Markovnikov-selective hydrothiolation in up to 88% yield and >20:1 regioselectivity. Conversely, when smaller bite angle ligands (βn ≤ 86°), for example, dppbz or dppp, are employed, the anti-Markovnikov product is formed in up to 74% yield and >20:1 regioselectivity. Initial mechanistic investigations are performed and are consistent with an oxidative addition/olefin insertion/reductive elimination mechanism for each regioisomeric pathway. We hypothesize that the change in regioselectivity is an effect of diverging coordination spheres to favor either Rh-S or Rh-H insertion to form the branched or linear isomer, respectively.
Asymmetric synthesis of α- And β-amino acids by diastereoselective addition of triorganozincates to N-(tert-butanesulfinyl) imines
Almansa, Raquel,Collados, Juan F.,Guijarro, David,Yus, Miguel
experimental part, p. 1421 - 1431 (2010/11/02)
The diastereoselective addition of triorganozincates to (R)-N-(tert-butanesulfinyl)imines has been used as a key step to achieve the synthesis of highly enantiomerically enriched N-protected α- and β-amino acids. Desulfinylation of the addition products followed by benzoylation of the nitrogen atom of the obtained primary amines and oxidation of one of the substituents on the carbon atom connected to the nitrogen complete the sequence. Using the same configuration in the sulfinyl chiral auxiliary, α-amino acids with the (R) or the (S) configuration can be prepared by choosing the proper combination of imine and organozincate. α,α- Disubstituted α-amino esters with high enantiomeric purity can also be prepared when α-imino esters are the starting substrates.
Application of the addition of triorganozincates to N-(tert-butanesulfinyl)imines to the enantioselective synthesis of α-amino acids
Almansa, Raquel,Guijarro, David,Yus, Miguel
scheme or table, p. 4188 - 4190 (2009/12/01)
Highly enantiomerically enriched N-protected α-amino acids can be easily prepared from optically pure N-(tert-butanesulfinyl)imines by a four-step sequence involving: diastereoselective addition of a triorganozincate to the imine, removal of the sulfinyl group, benzoylation of the nitrogen atom of the obtained primary amine and oxidation of one of the substituents on the carbon atom α to the nitrogen. Using the same configuration in the sulfinyl chiral auxiliary, amino acids with the (R) or the (S) configuration can be prepared by choosing the proper combination of imine and organozincate. α,α-Disubstituted α-amino esters with high optical purity can also be prepared by the diastereoselective addition of trialkylzincates to α-imino esters.
Enantioselective, iridium-catalyzed monoallylation of ammonia
Pouy, Mark J.,Stanley, Levi M.,Hartwig, John F.
scheme or table, p. 11312 - 11313 (2011/03/19)
(Chemical Equation Presented) Highly enantioselective, iridium-catalyzed monoallylations of ammonia are reported. These reactions occur with electron-neutral, -rich, and -poor cinnamyl carbonates, alkyl and trityloxy-substituted allylic carbonates, and di
A novel access to tetrahydro-β-carbolines via one-pot hydroformylation/fischer indole synthesis: Rearrangement of 3,3- spiroindoleninium cations
Bondzic, Bojan P.,Eilbracht, Peter
supporting information; experimental part, p. 3433 - 3436 (2009/05/07)
(Chemical Equation Presented) The two component one-pot hydroformylation/Fischer indole synthesis sequence of 2,5 dihydropyrroles and phenyl hydrazines allows a facile and convenient access to tetrahydro-β- carbolines in moderate to good yields.
Synthesis of highly enantiomerically enriched amines by the diastereoselective addition of triorganozincates to N-(tert-butanesulfinyl)imines
Almansa, Raquel,Guijarro, David,Yus, Miguel
experimental part, p. 2484 - 2491 (2009/04/11)
The reaction of triorganozincates with (R)-N-(tert-butanesulfinyl) imines gives the expected α-branched sulfinamides in good to excellent yields with diastereomeric ratios of up to 98:2. The N-sulfinyl group of the products can be easily removed by acidic treatment, affording the corresponding chiral primary amines in enantiomeric excesses of up to 96%. The reactivity and the selectivity shown by the triorganozincates are different from the ones observed with the corresponding Grignard reagents, which allows, in several cases, the preparation of both enantiomers of an amine from the same imine substrate. When mixed triorganozincates are used, one can take advantage of the slow transfer rate of the methyl group to use it as a non-transferable one. Both aromatic and aliphatic aldimines, as well as activated ketimines, are good substrates for these addition reactions.
Design, synthesis, and SAR of macrocyclic tertiary carbinamine BACE-1 inhibitors
Lindsley, Stacey R.,Moore, Keith P.,Rajapakse, Hemaka A.,Selnick, Harold G.,Young, Mary Beth,Zhu, Hong,Munshi, Sanjeev,Kuo, Lawrence,McGaughey, Georgia B.,Colussi, Dennis,Crouthamel, Ming-Chih,Lai, Ming-Tain,Pietrak, Beth,Price, Eric A.,Sankaranarayanan, Sethu,Simon, Adam J.,Seabrook, Guy R.,Hazuda, Daria J.,Pudvah, Nicole T.,Hochman, Jerome H.,Graham, Samuel L.,Vacca, Joseph P.,Nantermet, Philippe G.
, p. 4057 - 4061 (2008/02/10)
This Letter describes the design and synthesis of tertiary carbinamine macrocyclic inhibitors of the β-secretase (BACE-1) enzyme. These macrocyclic inhibitors, some of which incorporate novel P2 substituents, display a 2- to 100-fold increase in potency r
Enantioselective synthesis of 1-aryl-2-propenylamines: A new approach to a stereoselective synthesis of the Taxol side chain
Castagnolo, Daniele,Armaroli, Silvia,Corelli, Federico,Botta, Maurizio
, p. 941 - 949 (2007/10/03)
A variety of substituted 1-aryl-2-propenylamines of high enantiomeric purity were prepared via lipase-catalysed resolution of the corresponding racemates. (R)-1-Phenyl-2-propenylamine was further synthesised into (2R,3S)-3-benzoylamino-2-hydroxy-3-phenylpropanoic acid methyl ester, the side chain of Taxol.
Enantioselective synthesis of primary 1-(aryl)alkylamines by nucleophilic 1,2-addition of organolithium reagents to hydroxyoxime ethers and application to asymmetric synthesis of G-protein-coupled receptor ligands
Atobe, Masakazu,Yamazaki, Naoki,Kibayashi, Chihiro
, p. 5595 - 5607 (2007/10/03)
(E)-Arylaldehyde oxime ethers bearing a (1S)-2-hydroxy-1-phenylethyl or (2R)-1-hydroxy-2-phenylethyl group as a chiral auxiliary, both derived from a single precursor, methyl (R)-mandelate, underwent nucleophilic addition with organolithium reagents via six-membered chelates to give the diastereomerically enriched (R)- and (S)-adducts, respectively, which, after chiral auxiliary removal by reductive N-O bond cleavage, led to the corresponding (R)- and (S)-1-(aryl)ethylamines. This organolithium addition protocol using methyllithium was applied in an enantiodivergent fashion to the preparation of both enantiomers of 1-(2-hydroxyphenyl)ethylamine, which has been previously used as an efficient chiral auxiliary for the synthesis of natural products in this laboratory. The synthetic utility of this methodology involving diastereoselective methyl addition was demonstrated by further application to the asymmetric synthesis of a new type of calcium receptor agonist (calcimimetics), (R)-(+)-NPS R-568 and its thio analogue. Furthermore, diastereoselective vinylation was accomplished by application of the hydroxy oxime ether-based protocol using vinyllithium, which allowed the development of the enantioselective synthesis of the NK-1 receptor antagonists, (+)-CP-99,994 and (+)-CP-122,721.
