41496-45-1Relevant academic research and scientific papers
Three-Component, Interrupted Radical Heck/Allylic Substitution Cascade Involving Unactivated Alkyl Bromides
Bellotti, Peter,Glorius, Frank,Heidrich, Bastian,Huang, Huan-Ming,Pflüger, Philipp M.,Schwarz, J. Luca
supporting information, p. 10173 - 10183 (2020/06/27)
Developing efficient and selective strategies to approach complex architectures containing (multi)stereogenic centers has been a long-standing synthetic challenge in both academia and industry. Catalytic cascade reactions represent a powerful means of rapidly leveraging molecular complexity from simple feedstocks. Unfortunately, carrying out cascade Heck-type reactions involving unactivated (tertiary) alkyl halides remains an unmet challenge owing to unavoidable β-hydride elimination. Herein, we show that a modular, practical, and general palladium-catalyzed, radical three-component coupling can indeed overcome the aforementioned limitations through an interrupted Heck/allylic substitution sequence mediated by visible light. Selective 1,4-difunctionalization of unactivated 1,3-dienes, such as butadiene, has been achieved by employing different commercially available nitrogen-, oxygen-, sulfur-, or carbon-based nucleophiles and unactivated alkyl bromides (>130 examples, mostly >95:5 E/Z, >20:1 rr). Sequential C(sp3)-C(sp3) and C-X (N, O, S) bonds have been constructed efficiently with a broad scope and high functional group tolerance. The flexibility and versatility of the strategy have been illustrated in a gram-scale reaction and streamlined syntheses of complex ether, sulfone, and tertiary amine products, some of which would be difficult to access via currently established methods.
H-type zeolite-catalyzed 1,4-addition of benzene derivatives to labile acrolein
Hayashi, Daijiro,Narisawa, Tomoyuki,Masui, Yoichi,Onaka, Makoto
, p. 460 - 471 (2016/04/26)
The 1,4-addition of benzene derivatives to acrolein is a straightforward way to synthesize 3-arylpropanals. A survey of acid catalysts for the 1,4-addition of methoxy-substituted benzenes to acrolein revealed that H-Beta and H-Y were the most suitable catalysts. We hypothesized three side-reactions: (1) the double 1,4-addition of acrolein to the starting benzene derivatives, (2) the Friedel-Crafts-type alkylation to the desired product, and (3) the self-polymerization of acrolein. The type (3) side-reaction was inhibited by two different methods which kept the concentration of acrolein low in the reaction mixture or in the zeolite pores. First, acrolein monomers were in situ generated through the gradual monomerization of an acrolein cyclic trimer. Second, using a reaction solvent lowered the acrolein concentration in the zeolite pores due to the competitive adsorption. We discovered that the content of monomeric acrolein in a solvent was closely related to the polarity of the solvent. Actually, both methods improved the yields for the 1,4-additions of 1,3-dimethoxybenzene to acrolein. Other electron-rich benzene derivatives, such as phenol and N, N-dimethylaniline, were also applicable to the 1,4-addition reactions.
PYRAZOLO-TETRAHYDROPYRIDINE DERIVATIVES AS OREXIN RECEPTOR ANTAGONISTS
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Page/Page column 24, (2011/02/18)
The invention relates to novel pyrazolo-tetrahydropyridines compounds and their use as orexin receptor antagonists.
PYRAZOLO-TETRAHYDRO PYRIDINE DERIVATIVES AS OREXIN RECEPTOR ANTAGONISTS
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Page/Page column 11; 19, (2009/04/24)
The invention relates to novel pyrazolo-tetrahydropyridines compounds and their use as orexin receptor antagonists.
5,6,7,8-TETRAHYDRO-IMIDAZO[1,5-A]PYRAZINE DERIVATIVES
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Page/Page column 54, (2008/12/06)
The invention relates to 5,6,7,8-tetrahydro-imidazo[1,5-a]pyrazine derivatives of formula (I),wherein X represents CH2 or O; R1 represents a phenyl group, which group is independently mono-, di-, or tri-substituted wherein the substituents are independently selected from the group consisting of (C1-4)alkyl, (C1-4)alkoxy, halogen, cyano, trifluoromethoxy and trifluoromethyl; R2 represents (C1-4)alkyl, (C1-4)alkoxy, (C2-4)alkenyl, halogen, cyano, hydroxymethyl, trifluoromethyl, C(O)NR5R6 or cyclopropyl; R3 represents (C1-4)alkyl, (C1-4)alkoxy-methyl or halogen; R4 represents (C1-4)alkyl; R5 represents hydrogen or (C1-4)alkyl; and R6 represents hydrogen or (C1-4)alkyl. The invention also relates to pharmaceutically acceptable salts of such compounds; and to the use of such compounds as medicaments; especially as orexin receptor antagonists.
Synthesis of classical and nonclassical 2-amino-4-oxo-6-benzylthieno-[2,3- d]pyrimidines as potential thymidylate synthase inhibitors
Gangjee, Aleem,Qiu, Yibin,Kisliuk, Roy L.
, p. 941 - 946 (2007/10/03)
A series of seven nonclassical 2-amino-4-oxo-6-substituted thieno[2,3-d]pyrimidines 2-8 and one classical N-[4-(2-amino-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidin-6-ylmethyl)benzoyl]-L-glutamic acid 9 (Table I) were designed as the first in a series of 6-substituted 6-5 fused ring analogs as potential thymidylate synthase (TS) inhibitors and as antitumor agents. The target compounds were synthesized via a Heck coupling of appropriately substituted iodobenzenes and allyl alcohol followed by cyclization using cyanoacetate and sulfur powder to afford substituted thiophenes. The resulting thiophenes were then cyclocondensed with chloroformamidine hydrochloride to afford 2-amino-4-oxo-6-substituted thieno[2,3-d]pyrimidines 2-8 and 26. Hydrolysis of 26 followed by coupling with diethyl L-glutamate afforded 28. The classical analog 9 was obtained by hydrolysis of 28. None of the target compounds inhibited human recombinant thymidylate synthase at 23 μM except 9 for which the IC50 value was 100 μM.
96. Synthesis of 1,3,4,5-tetrahydro-2-benzoxepin derivatives as conformationally restricted analogues of cyclamenaldehyde-type compounds and as intermediates for highly odour-active homologues
Skouroumounis, Georges,Winter, Beat
, p. 1095 - 1109 (2007/10/03)
Nine 1,3,4,5-tetrahydro-2-benzoxepin derivatives have been prepared as mimics of the folded (gauche) conformation of cyclamenaldehyde (1) and related compounds, but none of them showed the typical lily-of-the valley (muguet) odour activity. However, conversion of these substances to previously unknown analogues of 1 having a Me substituent on the aromatic ring in an ortho position to the side chain led to new fragrance substances with remarkable properties. The results indicate that the extended (anti) conformation is more likely to be the 'bioactive' one at the receptor site(s).
A further breakthrough in biphasic, rhodium-catalyzed hydroformylation: The use of per(2,6-di-O-methyl)-β-cyclodextrin as inverse phase transfer catalyst
Monflier, Eric,Tilloy, Sebastien,Fremy, Georges,Castanet, Yves,Mortreux, Andre
, p. 9481 - 9484 (2007/10/02)
Solvent free biphasic hydroformylation of various water-insoluble terminal olefins can be achieved in high yields and selectivities by using a water-soluble rhodium/triphenylphosphine trisulfonate catalyst and per(2,6-di-o-methyl)-β-cyclodextrin as inverse phase transfer catalyst. The catalytic activities were up to ten times higher than those observed without per(2,6-di-o-methyl)-β-cyclodextrin.
