172823-12-0Relevant articles and documents
Direct catalytic enantioselective Mannich-type reaction of α,α-dithioacetonitriles with imines using chiral bis(imidazoline)-Pd complexes
Kondo, Masaru,Saito, Hikari,Nakamura, Shuichi
, p. 6776 - 6779 (2017)
The first highly enantioselective reaction of α,α-dithioacetonitriles with imines has been developed. Good yields and enantioselectivity were observed for the reaction of various imines using chiral bis(imidazoline) catalysts. The obtained products can be
Process Optimisation Studies and Aminonitrile Substrate Evaluation of Rhodococcus erythropolis SET1, A Nitrile Hydrolyzing Bacterium
Coady, Tracey M.,Coffey, Lee,Kinsella, Michael,Lennon, Claire M.,Mareya, Tatenda M.,O'Reilly, Catherine
, p. 512 - 520 (2020/10/02)
A comprehensive series of optimization studies including pH, solvent and temperature were completed on the nitrile hydrolyzing Rhodococcus erythropolis bacterium SET1 with the substrate 3-hydroxybutyronitrile. These identified temperature of 25 °C and pH of 7 as the best conditions to retain enantioselectivity and activity. The effect of the addition of organic solvents to the biotransformation mixture was also determined. The results of the study suggested that SET1 is suitable for use in selected organo-aqueous media at specific ratios only. The functional group tolerance of the isolate with unprotected and protected β-aminonitriles, structural analogues of β-hydroxynitriles was also investigated with disappointingly poor isolated yields and selectivity obtained. The isolate was further evaluated with the α- aminonitrile phenylglycinonitrile generating acid in excellent yield and ee (>99 % (S) – isomer and 50 % yield). A series of pH studies with this substrate indicated pH 7 to be the optimum pH to avoid product and substrate degradation.
Direct Catalytic Asymmetric Addition of Acetonitrile to Aldimines
Saito, Akira,Kumagai, Naoya,Shibasaki, Masakatsu
, p. 8187 - 8190 (2019/09/07)
Despite significant advances in catalytic asymmetric reactions with decent stereocontrol, those using acetonitrile as a pronucleophile are often disregarded due to their low reactivity and insufficient enantioselectivity. Herein we report the resurgence of this reaction in the chemical toolbox with high enantioselectivity (avg. > 95% ee). The combined use of a Ni(II) complex ligated with a chiral biscarbene and tBuOK engages acetonitrile in the catalytic generation of an α-cyanocarbanion and subsequent highly enantioselective addition to aldimines.
Ureidopeptide-based Bronsted bases: Design, synthesis and application to the catalytic enantioselective synthesis of β-amino nitriles from (arylsulfonyl)acetonitriles
Diosdado, Saioa,Lopez, Rosa,Palomo, Claudio
supporting information, p. 6526 - 6531 (2014/06/09)
The addition of cyanoalkyl moieties to imines is a very attractive method for the preparation of β-amino nitriles. We present a highly efficient organocatalytic methodology for the stereoselective synthesis of β-amino nitriles, in which the key to success is the use of ureidopeptide-based Bronsted base catalysts in combination with (arylsulfonyl)acetonitriles as synthetic equivalents of the acetonitrile anion. The method gives access to a variety of β-amino nitriles with good yields and excellent enantioselectivities, and broadens the stereoselective Mannich-type methodologies available for their synthesis. Learning from peptides: A concise route for the catalytic enantioselective synthesis of β-amino nitriles has been achieved by using ureidopeptide-based Bronsted bases as catalysts in the Mannich reaction of N-Boc imines and (arylsulfonyl)acetonitriles (see scheme; Boc=tert-butoxycarbonyl, napht=naphthyl, TMS=trimethylsilyl).
Catalytic enantioselective mannich-type reaction with β-phenyl sulfonyl acetonitrile
Gonzalez, Pedro B.,Lopez, Rosa,Palomo, Claudio
supporting information; experimental part, p. 3920 - 3922 (2010/08/06)
Figure presented The organocatalytic addition of β-phenyl sulfonyl acetonitrile 1 to either N-Boc-protected α-amido sulfones or imines allowed the synthesis of enantioenriched α-unsubstituted β-amino nitriles through a Mannich-type reaction.
Novel thiazolones as HCV NS5B polymerase allosteric inhibitors: Further designs, SAR, and X-ray complex structure
Yan, Shunqi,Larson, Gary,Wu, Jim Z.,Appleby, Todd,Ding, Yili,Hamatake, Robert,Hong, Zhi,Yao, Nanhua
, p. 63 - 67 (2007/10/03)
Structure-activity relationships (SAR) of 1 against HCV NS5B polymerase were described. SAR explorations and further structure-based design led to the identifications of 2 and 3 as novel HCV NS5B inhibitors. X-ray structure of 3 in complex with NS5B polymerase was obtained at a resolution of 2.2 A, and confirmed the design.
Preparation of an advanced phenylglycine-derived intermediate en route to the southern hemisphere tetraene of viridenomycin
Maw, Graham N.,Thirsk, Carl,Toujas, Jean-Louis,Vaultier, Michel,Whiting, Andrew
, p. 1183 - 1186 (2007/10/03)
A high-yielding synthesis of a phenylglycine derived (E,Z)-dienylboronate en route to the C16-C23 tetraene of the polyene macrolide viridenomycin is described. Crucial to this synthesis was the development of conditions enabling ready access to synthetically useful amino acid derivatives that should be widely applicable to other amino acids. These conditions confer advantages of increased yield and reliability over many of the existing literature alternatives, and also circumvent several of the problems encountered when dealing with such derivatives. The synthesis features a highly selective Heck coupling between an N-protected (Z)-alkenyl iodide and a hexylene glycol derived vinylboronate ester.
Synthesis of enantiopure N-and C-protected homo-β-amino acids by direct homologation of α-amino acids
Caputo, Romualdo,Cassano, Ersilia,Longobardo, Luigi,Palumbo, Giovanni
, p. 12337 - 12350 (2007/10/02)
Enantiopure N-and/or C-protected homo-β-amino acids are prepared readily and in good yields from N-protected α-amino acids with the same side chain, via reduction of the carboxyl function and conversion of the resulting N-protected β-amino alcohol into the corresponding β-amino iodide and then β-amino cyanide. The key step of this strategy is represented by the synthesis of the enantiopure N-protected β-amino iodides 2 and 3 that are smoothly obtained from the parent amino alcohols 1 by polymer bound triarylphosphine-I2 complex in anhydrous dichloromethane.
