- Preparation of isoquinazolines: Via metal-free [4 + 2] cycloaddition of ynamides with nitriles
-
TfOH-mediated [4 + 2] cycloaddition of ynamides with nitriles to construct 1,2-dihydroquinazolines is realized by a direct reaction in moderate to excellent yields (up to 93%) in a stereospecific manner. A rapid and efficient strategy has been employed for the syntheses of alkyl-substituted 1,2-dihydroquinazoline derivatives, and it exhibits good functional group tolerance, has a short reaction time, shows excellent diastereoselectivity, and is a simple and high-yielding reaction.
- Wu, Hao,Liu, Yu,He, Ming-Xing,Wen, Hao,Cao, Wei,Chen, Ping,Tang, Yu
-
p. 8408 - 8416
(2019/09/30)
-
- Hemilabile Benzyl Ether Enables Γ-C(sp3)-H Carbonylation and Olefination of Alcohols
-
Pd-catalyzed C(sp3)-H activation of alcohol typically shows β-selectivity due to the required distance between the chelating atom in the attached directing group and the targeted C-H bonds. Herein we report the design of a hemilabile directing group which exploits the chelation of a readily removable benzyl ether moiety to direct Γ- or δ-C-H carbonylation and olefination of alcohols. The utility of this approach is also demonstrated in the late-stage C-H functionalization of β-estradiol to rapidly prepare desired analogues that required multi-step syntheses with classical methods.
- Tanaka, Keita,Ewing, William R.,Yu, Jin-Quan
-
supporting information
p. 15494 - 15497
(2019/10/16)
-
- Hemilabile Benzyl Ether Enables γ-C(sp3)-H Carbonylation and Olefination of Alcohols
-
Pd-catalyzed C(sp3)-H activation of alcohol typically shows β-selectivity due to the required distance between the chelating atom in the attached directing group and the targeted C-H bonds. Herein we report the design of a hemilabile directing group which exploits the chelation of a readily removable benzyl ether moiety to direct γ- or δ-C-H carbonylation and olefination of alcohols. The utility of this approach is also demonstrated in the late-stage C-H functionalization of β-estradiol to rapidly prepare desired analogues that required multi-step syntheses with classical methods.
- Tanaka, Keita,Ewing, William R.,Yu, Jin-Quan
-
supporting information
(2019/10/22)
-
- Catalytic Reduction of Alkyl and Aryl Bromides Using Propan-2-ol
-
Milstein's complex, (PNN)RuHCl(CO), catalyzes the efficient reduction of aryl and alkyl halides under relatively mild conditions by using propan-2-ol and a base. Sterically hindered tertiary and neopentyl substrates are reduced efficiently, as well as more functionalized aryl and alkyl bromides. The reduction process is proposed to occur by radical abstraction/hydrodehalogenation steps at ruthenium. Our research represents a safer and more sustainable alternative to typical silane, lithium aluminium hydride, and tin-based conditions for these reductions.
- Haibach, Michael C.,Stoltz, Brian M.,Grubbs, Robert H.
-
p. 15123 - 15126
(2017/11/20)
-
- CYCLOALKYL METHOXYBENZYL PHENYL PYRAN DERIVATIVES AS SODIUM DEPENDENT GLUCOSE CO TRANSPORTER (SGLT2) INHIBITORS
-
The invention relates to the cycloalkyl methoxybenzyl phenyl pyran derivatives as Sodium dependent glucose co transporter (SGLT) inhibitors, particularly SGLT2 and method of treating diseases, conditions and/or disorders inhibited by SGLT2 with them, and processes for preparing them.
- -
-
-
- ANDROGEN RECEPTOT-ABLATIVE AGENTS
-
Compounds of the thiazolidinedione family are provided and shown to be effective androgen receptor ablative agents that can be used in methods of treating or preventing cancer or precancer, including prostate cancer. Also provided are methods of treating
- -
-
Page/Page column 29; 39
(2009/10/18)
-
- Pharmacological exploitation of the peroxisome proliferator-activated receptor γ agonist ciglitazone to develop a novel class of androgen receptor-ablative agents
-
On the basis of our finding that the peroxisome proliferator-activated receptor γ (PPARγ) agonist ciglitazone at high doses was able to mediate PPARγ-independent transcriptional repression of androgen receptor (AR) in a tumor cell-specific manner, we used
- Yang, Jian,Wei, Shuo,Wang, Da-Sheng,Wang, Yu-Chieh,Kulp, Samuel K.,Chen, Ching-Shih
-
p. 2100 - 2107
(2008/12/22)
-
- Practical and efficient method for amino acid derivatives containing β-quaternary center: application toward synthesis of hepatitis C virus NS3 serine protease inhibitors
-
A practical and efficient route toward synthesis of amino acid derivatives containing β-quaternary center has been developed using diastereoselective Strecker reaction. The method was employed for preparation of >100 g of β-methylcyclohexyl glycine deriva
- Arasappan, Ashok,Venkatraman, Srikanth,Padilla, Angela I.,Wu, Wanli,Meng, Tao,Jin, Yan,Wong, Jesse,Prongay, Andrew,Girijavallabhan, Viyyoor,George Njoroge
-
p. 6343 - 6347
(2008/02/10)
-
- NOVEL COMPOUNDS AS INHIBITORS OF HEPATITIS C VIRUS NS3 SERINE PROTEASE
-
The present invention discloses novel compounds which have HCV protease inhibitory activity as well as methods for preparing such compounds. In another embodiment, the invention discloses pharmaceutical compositions comprising such compounds as well as methods of using them to treat disorders associated with the HCV protease.
- -
-
Page/Page column 88-89
(2008/06/13)
-
- NOVEL KETOAMIDES WITH CYCLIC P4'S AS INHIBITORS OF NS3 SERINE PROTEASE OF HEPATITIS C VIRUS
-
The present invention discloses novel compounds which have HCV protease inhibitory activity as well as methods for preparing such compounds. In another embodiment, the invention discloses pharmaceutical compositions comprising such compounds as well as methods of using them to treat disorders associated with the HCV protease.
- -
-
Page/Page column 76-77
(2008/06/13)
-
- CYCLOBUTENEDIONE GROUPS-CONTAINING COMPOUNDS AS INHIBITORS OF HEPATITIS C VIRUS NS3 SERINE PROTEASE
-
The present invention discloses novel compounds which have HCV protease inhibitory activity as well as methods for preparing such compounds. In another embodiment, the invention discloses pharmaceutical compositions comprising such compounds as well as methods of using them to treat disorders associated with the HCV protease.
- -
-
Page/Page column 78
(2010/02/14)
-
- NOVEL COMPOUNDS AS INHIBITORS OF HEPATITIS C VIRUS NS3 SERINE PROTEASE
-
The present invention discloses novel compounds which have HCV protease inhibitory activity as well as methods for preparing such compounds. In another embodiment, the invention discloses pharmaceutical compositions comprising such compounds as well as methods of using them to treat disorders associated with the HCV protease.
- -
-
Page/Page column 75
(2010/02/14)
-
- Construction of a quaternary carbon center via cyclic sulfite
-
Reaction of (S)-2-oxo-4-methyl-4-phenyl-1,3,2-dioxathiolane with triethylaluminum selectively took place at the tertiary carbinol center to give (R)-2-methyl-2-phenyl-1-butanol. Enhanced stereoselectivity was obtained in a nonpolar solvent. Similarly, a series of (S)-4,4-disubstituted-1,3,2- dioxathiolanes reacted with trimethylaluminum to afford the corresponding (R)-2-alkyl-2-phenyl-1-propanols in good yields. (C) 2000 Elsevier Science Ltd.
- Nishimura, Nanae,Mitsunobu, Oyo
-
p. 2945 - 2948
(2007/10/03)
-
- Synthesis of the novel analogues of dysidiolide and their structure-activity relationship
-
The novel analogues of natural cdc25A inhibitor dysidiolide were synthesized. To investigate the structure-activity relationship, the inhibitory activity to enzyme and cell cycle was examined. (C) 2000 Elsevier Science Ltd.
- Takahashi, Masato,Dodo, Kosuke,Sugimoto, Yoshikazu,Aoyagi, Yoshimi,Yamada, Yuji,Hashimoto, Yuichi,Shirai, Ryuichi
-
p. 2571 - 2574
(2007/10/03)
-
- Novel and facile selective reduction of carboxylic acid with a samarium diiodide-lanthanide triflate-methanol-base system
-
The facile selective reduction of carboxylic acids in the presence of an aldehyde or that bearing a formyl group proceeded smoothly with a samarium diiodide-lanthanide triflate-methanol-base system at room temperature to give the corresponding alcohols in good to almost quantitative yield.
- Kamochi, Yasuko,Kudo, Tadahiro
-
p. 341 - 344
(2007/10/03)
-
- Alkane Functionalization on a Preparative Scale by Mercury-Photosensitized Cross-Dehydrodimerization
-
Alkanes can be functionalized with high conversions and in high chemical and quantum yields on a multigram scale by mercury-photosensitized reaction between an alkane and alcohols, ethers, or silanes to give homodimers and cross-dehydrodimers.The separation of the product mixtures is often particulary easy because of a great difference in polarity of the homodimers and cross-dimers.It is also possible to bias the product composition when the ratio of the components in the vapor phase is adjusted by altering the liquid composition.This is useful either to maximize chemical yield or to ease separation by favoring the formation of the most easily separated pair of compounds.The mechanistic basis of the reaction is discussed and a number of specific types of syntheses, for example of 2,2-disubstituted carbinols, are described in detail.The selectivity of cross-dimerization is shown to exceed that for homodimerization and reasons are discussed.Relative reactivities of different compounds and classes of compound are MeOHp-dioxanecyclohexane1,3,5-trioxacyclohexaneethanolisobutaneTHFEt3SiH.The observed selectivities generally parallel those for homodimerization, reported in the preceding paper, but certain differences are noted, and reasons for the differences are proposed.The bond-dissociation energy of Et3SiH is estimated from the reactivity data to be 90 kcal/mol.Eleven new carbinols are synthesized.
- Brown, Stephen H.,Crabtree, Robert H.
-
p. 2946 - 2953
(2007/10/02)
-
- Bicyclo-octane and bicyclo-nonane derivatives, processes for their preparation and their use as herbicides
-
Bicyclo-octane and bicyclo-nonane derivatives are described having herbicidal and plant growth regulating properties. The derivatives are based on the general formula
- -
-
-
- Alkane Functionalisation on a Preparative Scale by Mercury Photosensitisation
-
Alkanes can be functionalised on a multigram scale by mercury photosensitised cross-dimerisation with alcohols, ethers and silanes.
- Brown, Stephen H.,Crabtree, Robert H.
-
p. 970 - 971
(2007/10/02)
-
- EFFICIENT SYNTHESIS OF SOME 2-OXASPIRONONA-1-ONES AS ANISATIN MODELS
-
As a model study for the synthesis of anisatin, 2-oxaspirononane and 5-hydroxy-5-methyl-2-oxaspirononane were synthesized from methyl cyclohexanecarboxylate and 2-ethoxycarbonylcyclohexanone, respectively, and these oxenates were submitted to ru
- Kato, Michiharu,Kitahara, Haruo,Yoshikoshi, Akira
-
p. 1785 - 1788
(2007/10/02)
-
- Deuterium Isotope Effects for Migrating and Nonmigrating Groups in the Solvolysis of Neopentyl-Type Esters
-
α- and γ-deuterium rate effects on the solvolysis of (1-methylcyclohexyl)methyl, (1-methylcyclopentyl)methyl, and (1-methylcyclobutyl)methyl sulfonate esters have been measured and the solvolysis products examined by 2H NMR spectroscopy.The results indicate that the products of the solvolysis of all these sulfonate esters are predominantely ((*) 98percent) rearranged.In the solvolysis of (1-methylcyclohexyl)methyl triflate, rearranged products with methyl migration slightly dominate over those with ring expansion.Normal isotope effects, 1.057 in 80E and 1.073 in 97T, are observed for the methyl-d3 compound and an inverse effect, 0,963, is observed in 80E for the methylene-d4 compound.However, in the solvolysis of both (1-methylcyclopentyl)methyl and (1-methylcyclobutyl)methyl sulfonates, the major products are those of ring expansion.In these examples, inverse effects are observed for the methyl-d3-labeled species.The observed isotope effects can be separated into respective values of 0.927, 0.913 for the nonmigrating methyl-d3 group and 1.177, 1.224 for the migrating methyl-d3 group in the solvolysis of (1-methylcyclohexyl)methyl triflate and (1-methylcyclopentyl)methyl brosylate.This explains the relative intramolecular migratory aptitudes of CH3/CD3 of 1.20 - 1.30 and the low γ-d9 isotope effect in the solvolysis of neopentyl sulfonates previously reported and makes them consistent with a mechanism which involves neighboring carbon participation during ionization.
- Shiner, V. J.,Tai, Jimmy J.
-
p. 436 - 442
(2007/10/02)
-
- Alumina: Catalyst and support. XL (1) ring expansion during the dehydration of alcohols over alumina catalysts (2)
-
An investigation of ring expansion during the alumina-catalyzed dehydration of alcohols was made by the micro-pulse technique. The dehydration at 380 °C over fresh alumina of cyclobutane-, cyclopentane-, cyclohexane-, and cycloheptane-methanol yielded 99, 55, 7, and 6% of ring-expanded product, respectively, whereas over alumina which has been deactivated by passing large quantities of alcohol over it, 100, 74, 19, and 18% of the ring-expanded products were found. The stereochemical aspects of this catalytic reaction were investigated by the dehydration of cis- and trans-4-t-butylcyclohexanemethanol. More ring expansion and a higher conversion to olefins occurred in the dehydration of the cis alcohol than of the trans alcohol. In the dehydration of 1-methyl-1-cyclohexanemethanol at 310 °C, 60% of product formation involved methyl migration whereas 40% involved ring expansion. The percentage of ring expansion increased to 55 when deactivated catalyst was used. More skeletal rearrangement was found in dehydrations over alumina which had been deactivated by passing either an unsaturated or a saturated hydrocarbon over it than when fresh catalyst was used. Although the presence of sodium ions or pyridine on the catalyst lowered the amount of double bond isomerization which occurred, it did not affect the amount of skeletal rearrangement or the deactivation of the catalyst. The dehydration of 2-methylpropanol over alumina catalyst was reinvestigated and it was found that the extent of skeletal isomerization to produce n-butenes increases with the deactivation of the aluminas.
- Pines, Herman,Brown, Stanley M.
-
-