63658-18-4Relevant articles and documents
Silver-Promoted Direct Phosphorylation of Bulky C(sp2)-H Bond to Build Fully Substituted β-Phosphonodehydroamino Acids
Cao, Hao-Qiang,Liu, Hao-Nan,Liu, Zhe-Yuan,Qiao, Baokun,Zhang, Fa-Guang,Ma, Jun-An
supporting information, p. 6414 - 6419 (2020/09/02)
A general and practical cross-dehydrogenative coupling protocol between readily available trisubstituted α,β-dehydro α-amino carboxylic esters and H-phosphites is described. This C(sp2)-H phosphorylation reaction proceeds with absolute Z-selectivity promoted by silver salt in a radical relay manner. The bulky tetrasubstituted β-phosphonodehydroamino acids were obtained in grams and added new modules to the toolkit for peptide modifications.
Chemo- and Enantioselective Hydrogenation of α-Formyl Enamides: An Efficient Access to Chiral α-Amido Aldehydes
Zhang, Jian,Jia, Jia,Zeng, Xincheng,Wang, Yuanhao,Zhang, Zhenfeng,Gridnev, Ilya D.,Zhang, Wanbin
supporting information, p. 11505 - 11512 (2019/07/17)
In order to effectively synthesize chiral α-amino aldehydes, which have a wide range of potential applications in organic synthesis and medicinal chemistry, a highly chemo- and enantioselective hydrogenation of α-formyl enamides has been developed, catalyzed by a rhodium complex of a P-stereogenic bisphosphine ligand. Under different hydrogen pressures, the chiral α-amido aldehydes and β-amido alcohols were obtained in high yields (97–99 %) and with excellent chemo- and enantioselectivities (up to >99.9 % ee). The hydrogenation can be carried out on a gram scale and with a high substrate/catalyst ratio (up to 20 000 S/C), and the hydrogenated products were further converted into several important chiral products. Computations of the catalytic cycle gave a clear description for the R/S pathways, provided a reasonable explanation for the enantioselectivity, and revealed several other specific features.
BABIPhos Family of Biaryl Dihydrobenzooxaphosphole Ligands for Asymmetric Hydrogenation
Li, Guisheng,Zatolochnaya, Olga V.,Wang, Xiao-Jun,Rodríguez, Sonia,Qu, Bo,Desrosiers, Jean-Nicolas,Mangunuru, Hari P. R.,Biswas, Soumik,Rivalti, Daniel,Karyakarte, Shuklendu D.,Sieber, Joshua D.,Grinberg, Nelu,Wu, Ling,Lee, Heewon,Haddad, Nizar,Fandrick, Daniel R.,Yee, Nathan K.,Song, Jinhua J.,Senanayake, Chris H.
supporting information, p. 1725 - 1729 (2018/04/14)
Novel bidentate phosphine ligands BABIPhos featuring a biaryl bis-dihydrobenzooxaphosphole core are presented. Their synthesis was achieved via Pd-catalyzed reductive homocoupling of dihydrobenzooxaphosphole aryl triflates. An efficient route toward various analogues was also established, giving access to phosphines with different electronic and steric properties. The newly obtained ligands demonstrated high efficiency and selectivity in Rh-catalyzed asymmetric hydrogenation of di- and trisubstituted enamides. This new class of ligands is complementary to previously described bidentate benzooxaphosphole ligands BIBOP.
Elucidation of Racemization Process of Azaspirene Skeleton in Neutral Aqueous Media
Hirasawa, Shun,Mukai, Ken,Sakai, Shinnosuke,Wakamori, Shinnosuke,Hasegawa, Takahiro,Souma, Kazunori,Kanomata, Nobuhiro,Ogawa, Narihito,Aizawa, Mamoru,Emoto, Makoto
, p. 14457 - 14464 (2019/01/03)
Azaspirene and related congeners, which possess various biological activities, have a unique spirocyclic core structure. However, there are few studies on the chemical properties of (-)-azaspirene, despite the fact that it may provide important insights into unveiling the biosynthetic pathway. Here, we report a nine-step chemical synthesis of an azaspirene analogue with a new finding that the natural (-)-azaspirene skeleton easily racemizes in neutral aqueous media.
The Role of the Amino Protecting Group during Parahydrogenation of Protected Dehydroamino Acids
Cerutti, Erika,Viale, Alessandra,Nervi, Carlo,Gobetto, Roberto,Aime, Silvio
, p. 11271 - 11279 (2015/12/01)
A series of dehydroamino acids endowed with different protective groups at the amino and carboxylate moieties and with different substituents at the double bond have been reacted with parahydrogen. The observed ParaHydrogen Induced Polarization (PHIP) effects in the 1H NMR spectra are strongly dependent on the amino protecting group. DFT calculations allowed us to establish a relationship between the structures of the reaction intermediates (whose energies depend on the amido substitution) and the observed PHIP patterns.
Copper-catalyzed asymmetric hydroboration of α-dehydroamino acid derivatives: Facile synthesis of chiral β-hydroxy-α-amino acids
He, Zhi-Tao,Zhao, Yi-Shuang,Tian, Ping,Wang, Chuan-Chuan,Dong, Han-Qing,Lin, Guo-Qiang
supporting information, p. 1426 - 1429 (2014/04/03)
The Cu-catalyzed asymmetric conjugate hydroboration reaction of β-substituted α-dehydroamino acid derivatives has been established, affording enantioenriched syn- and anti-β-boronate-α-amino acid derivatives with excellent combined yields (83-99%, dr ≈ 1:
CHIRAL FLUORINATING REAGENTS
-
, (2014/05/24)
This invention relates to fluorinating agents and, more particularly, to chiral non-racemic fluorinating agents useful for enantioselective fluorination, as well as to their synthesis and use and other subject matter. The fluorinating agents are based on a substituted 1,4-diazabicyclo[2.2.2]octane (DABCO) skeleton and provide electrophillic fluorine enantioselectively.
Selective reactivity of electron-rich aryl iodides in the Heck arylation of disubstituted alkenes catalyzed by palladium-arylurea complexes
Smith, Matthew R.,Jang, Young Jin,Kim, Jung Yun,Ciufolini, Marco A.
, p. 10139 - 10151 (2013/11/06)
A catalyst consisting of 1 mol % of the 1:2 complex of Pd(OAc)2 with N-(4-carbethoxyphenyl)urea promotes the Heck arylation of 2- or 3-substituted, conjugated esters, nitriles, aldehydes, and ketones (an uncharacteristically broad range of substrates), but only with electron-rich aryl iodides (an uncharacteristically narrow range of halides).
Solvent-free synthesis of unsaturated amino esters in a ball-mill
Baron, Alice,Martinez, Jean,Lamaty, Frédéric
scheme or table, p. 6246 - 6249 (2011/01/04)
The ball-milling technique was used under solvent-free conditions to perform a Horner-Wadsworth-Emmons reaction in the presence of a mild carbonate base. Starting from a phosphonate-substituted glycine, this method gave access to Boc-protected unsaturated
Discovery of pyrrolopyrimidine inhibitors of Akt
Blake, James F.,Kallan, Nicholas C.,Xiao, Dengming,Xu, Rui,Bencsik, Josef R.,Skelton, Nicholas J.,Spencer, Keith L.,Mitchell, Ian S.,Woessner, Richard D.,Gloor, Susan L.,Risom, Tyler,Gross, Stefan D.,Martinson, Matthew,Morales, Tony H.,Vigers, Guy P.A.,Brandhuber, Barbara J.
scheme or table, p. 5607 - 5612 (2010/11/17)
The discovery and optimization of a series of pyrrolopyrimidine based protein kinase B (Pkb/Akt) inhibitors discovered via HTS and structure based drug design is reported. The compounds demonstrate potent inhibition of all three Akt isoforms and knockdown of phospho-PRAS40 levels in LNCaP cells and tumor xenografts.
