6540-31-4Relevant academic research and scientific papers
α-Tetrasubstituted Aldehydes through Electronic and Strain-Controlled Branch-Selective Stereoselective Hydroformylation
Eshon, Josephine,Foarta, Floriana,Landis, Clark R.,Schomaker, Jennifer M.
, p. 10207 - 10220 (2018/09/06)
Hydroformylation utilizes dihydrogen, carbon monoxide, and a catalyst to transform alkenes into aldehydes. This work applies chiral bisdiazaphospholane (BDP)- and bisphospholanoethane-ligated rhodium complexes to the hydroformylation of a variety of alkenes to produce chiral tetrasubstituted aldehydes. 1,1′-Disubstituted acrylates bearing electron-withdrawing substituents undergo hydroformylation under mild conditions (1 mol % of catalyst/BDP ligand, 150 psig gas, 60 °C) with high conversions and yields of tetrasubstituted aldehydes (e.g., 13:1 regioselectivity, 85% ee, and 99% regioselectivity and >19:1 diastereoselectivity to tetrasubstituted aldehydes at rates >50 catalyst turnovers/hour. NMR studies of the noncatalytic reaction of HRh(BDP)(CO)2 with methyl 1-fluoroacrylate enable interception of tertiary alkylrhodium intermediates, demonstrating migratory insertion to acyl species is slower than formation of secondary and primary alkylrhodium intermediates. Overall, these investigations reveal how the interplay of sterics, electronics, and ring strain are harnessed to provide access to valuable α-tetrasubstituted aldehyde synthetic building blocks by promoting branched-selective hydroformylation.
SYNTHESIS OF TELAPREVIR AND BOCEPREVIR, OR PHARMACEUTICALLY ACCEPTABLE SALTS OR SOLVATES AS WELL AS INTERMEDIATE PRODUCTS THEREOF INCLUDING ?-AMINO ACIDS PREPARED VIA MUKAIYAMA ALDOL ADDITION
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Page/Page column 51, (2014/01/09)
The invention relates to synthetic routes for preparing telaprevir and boceprevir, and its intermediates as well as peptides other than telaprevir. The synthetic routes are based on a Mukaiyama aldol addition reaction of a silyl enol ether or an enolate with an imine. The invention also refers to novel intermediates for preparing telaprevir/boceprevir or other peptides.
Discovery of novel thieno[2,3-d]pyrimidin-4-yl hydrazone-based cyclin-dependent kinase 4 inhibitors: synthesis, biological evaluation and structure-activity relationships
Horiuchi, Takao,Takeda, Yasuyuki,Haginoya, Noriyasu,Miyazaki, Masaki,Nagata, Motoko,Kitagawa, Mayumi,Akahane, Kouichi,Uoto, Kouichi
experimental part, p. 991 - 1002 (2011/10/02)
The design, synthesis, and evaluation of novel thieno[2,3-d]pyrimidin-4-yl hydrazone analogues as cyclin-dependent kinase 4 (CDK4) inhibitors are described. In continuing our program aim to search for potent CDK4 inhibitors, the introduction of a thiazole group at the hydrazone part has led to marked enhancement of chemical stability. Furthermore, by focusing on the optimization at the C-4′ position of the thiazole ring and the C-6 position of the thieno[2,3-d]pyrimidine moiety, compound 35 has been identified with efficacy in a xenograft model of HCT116 cells. In this paper, the potency, selectivity profile, and structure-activity relationships of our synthetic compounds are discussed.
Discovery of new antitubercular oxazolyl thiosemicarbazones
Sriram, Dharmarajan,Yogeeswari, Perumal,Thirumurugan, Rathinasababathy,Pavana, Roheet Kumar
, p. 3448 - 3450 (2007/10/03)
Twenty 4-(5-cyclobutyloxazol-2-yl)thiosemicarbazones were synthesized and evaluated for preliminary in vitro and in vivo activity against Mycobacterium tuberculosis H37Rv (MTB) and multidrug-resistant Mycobacterium tuberculosis (MDR-TB). Among them, (4-br
