- Ph3PAuNTf2 as a superior catalyst for the selective synthesis of 2H-chromenes: Application to the concise synthesis of benzopyran natural products
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Ph3PAuNTf2 (≈1 mol-%) catalyzes the selective cycloisomerization of substituted aryl propargyl ethers into 2H-chromenes in excellent yields. Benzofuran byproducts are formed only in the case of electron-deficient arenes, in up to 7% relative yield. The Ph 3PAuNTf2-catalyzed cyclization of aryl propargyl ethers was applied as a key step to the concise synthesis of the naturally occurring benzopyrans seselin, xanthyletin, precocenes I and II, 8-(3′,3′- dimethylallyl)wenteria chromene, and 2,2-dimethyl-8-prenylchromene-6-propenoic acid. Ph3PAuNTf2 is a general, highly efficient, and product-selective catalyst for the clean synthesis of 2H-chromenes from the cycloisomerization of aryl propargyl ethers.The Ph3PAuNTf 2-catalyzed cyclization was applied as a key step in the synthesis of several benzopyran-bearing naturally occurring substances. Copyright
- Lykakis, Ioannis N.,Efe, Christina,Gryparis, Charis,Stratakis, Manolis
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experimental part
p. 2334 - 2338
(2011/06/20)
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- Gold nanoparticles supported on TiO2 catalyse the cycloisomerisation/oxidative dimerisation of aryl propargyl ethers
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Gold nanoparticles supported on TiO2 (~1%) catalyse in high yields the selective cycloisomerisation of aryl propargyl ethers into the corresponding 2H-chromenes, under heterogeneous conditions. 2H,2′H-3, 3′-Bichromenes resulting from a catalytic oxidative dimerization pathway are also formed as by-products. The Royal Society of Chemistry 2011.
- Efe, Christina,Lykakis, Ioannis N.,Stratakis, Manolis
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supporting information; body text
p. 803 - 805
(2011/04/12)
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- NON-NUCLEOTIDE REVERSE TRANSCRIPTASE INHIBITORS
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Compounds of the formula Z: where; A is CH or N; R1 is a substituent to a carbon atom in the ring containing A selected from -S(=O)pRa, where Ra is -C1-C4 alkyl, -ORx, -NRxRx, -NHNRxRx, - NHNHC(=O)ORx, -NRxOH; -C(=O)-Rb, where Rb is -CT-C4-alkyl, ORx, -NRxRx, -NHNRxRx, -NHC1-C3-alkyl-C(=O)Orx -NRxRc, where Rc is H, C1-C4 alkyl, -NRxRx; -C(=0)Rd, -CN, S(=O)pRx where Rd is Rd is C1-C4-alkyl, -ORx, -NRxRx C1-C3-alkyl-O-Cl-C3alkylC(=O)ORx, -C1-C3-alkyl-COORx; -C1-C3alkyl-OH or C1-C4 alkyl ethers or esters thereof (O-Cl-C3alkyl)q-O-Rx a 5 or 6 membered aromatic ring having 1-3 hetero atoms p is 1 or 2; Rx is independently selected from H, C1-C4 alkyl or acetyl; or a pair of Rx can together with the adjacent N atom form a ring; L is -0-, -S(=O),- or -CH2-, where r is 0, 1 or 2; R3-R7 are substituents as defined in the specification; X is -(CR8R8')n-D-(CR8R8')m-; D is a bond, -NR9-, -0-, -S-, -S(=0)- or -S(=0)2-; and pharmaceutically acceptable salts and prodrugs thereof, have utility as HIV antivirals.
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Page/Page column 64
(2008/06/13)
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- Non-nucleoside reverse transcriptase inhibitors
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Compounds of the formula I: where; R1 is O, S; R2 is an optionally substituted nitrogen-containing heterocycle, wherein the nitrogen is located at the 2 position relative to the (thio)urea bond; R3 is H, C1-C3 alkyl, R4-R7 are independently selected from H, C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, haloC1-C6 alkyl, C1-C6 alkanoyl, haloC1-C6 alkanoyl, C1-C6 alkoxy, haloC1-C6 alkoxy, C1-C6 alkyloxy-C1-C6 alkyl, haloC1-C6 alkyloxy-C1-C6 alkyl hydroxy-C1-C6 alkyl, amino-C1-C6 alkyl, carboxy-C1-C6 alkyl, cyano-C1-C6 alkyl, amino, carboxy, carbamoyl, cyano, halo, hydroxy, keto; X is —(CHR8)n-—D—(CHR8)m—; D is —NR9—, —O—, —S—, —S(═O)— or —S(═O)2—; R8 is independently H, C1-C3 alkyl, halo substitutedC1-C3alkyl; R9 is H, C1-C3 alkyl; n and m are independently 0, 1 or 2; and prodrugs and pharmaceutically acceptable salts thereof, have utility as inhibitors of HIV-1 reverse transcriptase, particularly drug escape mutants.
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