134030-39-0Relevant academic research and scientific papers
Stereoselective cyclopropanation and ring-opening: Application to the synthesis of pure (S)-2-methyl-3-arylpropylamines
Roje, Marin,Vinkovic, Vladimir,Sunjic, Vitomir,Solladie-Cavallo, Arlette,Diep-Vohuule, Anh,Isarno, Thomas
, p. 9123 - 9128 (1998)
Stereoselective catalytic and stoichiometric cyclopropanation of styrenes 3a,3b was studied; the stoichiometric method turned out superior in the terms of enantioselectivity. The intermediate carboxymethyl cyclopropane 11a,11b, obtained on reduction of carbethoxy derivatives 4a,4b, were hydrogenolyzed to (S)-1,3-substituted-2-methylpropanes 15a,15b. The highest conversion and regioselectivity was obtained with 3% Pd/C as the catalyst. The final steps, chlorination of alcohol 15a into 19a, and alkylation of cyclic sec amines were already demonstrated by us (ref. 2c) to afford (S)-(- )-2-(4-tert-butylphenyl)-1-cis-2,6-dimethylmorpholyl)propane (S-1a) and (S)- (-)-2-(4-tert-butylphenyl)-1-piperidylpropane (S-2a), the (S)-enantiomers of two systemic fungicides presently commercialized as racemates, without any lost of enantiomeric purity.
Radical-Mediated Strategies for the Functionalization of Alkenes with Diazo Compounds
Su, Yong-Liang,Liu, Geng-Xin,Liu, Jun-Wen,Tram, Linh,Qiu, Huang,Doyle, Michael P.
supporting information, p. 13846 - 13855 (2020/09/21)
One of the most common reactions of diazo compounds with alkenes is cyclopropanation, which occurs through metal carbene or free carbene intermediates. Alternative functionalization of alkenes with diazo compounds is limited, and a methodology for the addition of the elements of Z-CHR2 (with Z = H or heteroatom, and CHR2 originates from N2 CR2) across a carbon-carbon double bond has not been reported. Here we report a novel reaction of diazo compounds utilizing a radical-mediated addition strategy to achieve difunctionalization of diverse alkenes. Diazo compounds are transformed to carbon radicals with a photocatalyst or an iron catalyst through PCET processes. The carbon radical selectively adds to diverse alkenes, delivering new carbon radical species, and then forms products through hydroalkylation by thiol-assisted hydrogen atom transfer (HAT), or forms azidoalkylation products through an iron catalytic cycle. These two processes are highly complementary, proceed under mild reaction conditions, and show high functional group tolerance. Furthermore, both transformations are successfully performed on a gram-scale, and diverse γ-amino esters, γ-amino alcohols, and complex spirolactams are easily prepared with commercially available reagents. Mechanistic studies reveal the plausible pathways that link the two processes and explain the unique advantages of each.
Design and synthesis of novel antimicrobials with activity against Gram-positive bacteria and mycobacterial species, including M. tuberculosis
Tiruveedhula, V.V.N. Phani Babu,Witzigmann, Christopher M.,Verma, Ranjit,Kabir, M. Shahjahan,Rott, Marc,Schwan, William R.,Medina-Bielski, Sara,Lane, Michelle,Close, William,Polanowski, Rebecca L.,Sherman, David,Monte, Aaron,Deschamps, Jeffrey R.,Cook, James M.
, p. 7830 - 7840 (2014/01/06)
The alarming increase in bacterial resistance over the last decade along with a dramatic decrease in new treatments for infections has led to problems in the healthcare industry. Tuberculosis (TB) is caused mainly by Mycobacterium tuberculosis which is responsible for 1.4 million deaths per year. A world-wide threat with HIV co-infected with multi and extensively drug-resistant strains of TB has emerged. In this regard, herein, novel acrylic acid ethyl ester derivatives were synthesized in simple, efficient routes and evaluated as potential agents against several Mycobacterium species. These were synthesized via a stereospecific process for structure activity relationship (SAR) studies. Minimum inhibitory concentration (MIC) assays indicated that esters 12, 13, and 20 exhibited greater in vitro activity against Mycobacterium smegmatis than rifampin, one of the current, first-line anti-mycobacterial chemotherapeutic agents. Based on these studies the acrylic ester 20 has been developed as a potential lead compound which was found to have an MIC value of 0.4 μg/mL against Mycobacterium tuberculosis. The SAR and biological activity of this series is presented; a Michael-acceptor mechanism appears to be important for potent activity of this series of analogs.
