- N-Methylpiperidine assisted catalytic multicomponent reaction
-
Abstract: A catalytic methodology involving terminal alkynes, elemental sulfur, and three-membered heterocycles has been described. This domino transformation serves as a useful method for the synthesis of oxathiolane and thiazolidine derivatives from the readily available starting materials. In situ generated copper acetylides reacted with elemental sulfur and oxiranes or aziridines in the presence of N-methylpiperidine as sulfur activating agent to form synthetically important heterocycles.
- Keshtegar, Zahra,Heydari, Reza,Samzadeh-Kermani, Alireza
-
-
Read Online
- An expeditious one-pot synthesis of thiiranes from α-halo ketones in solvent-free conditions using microwaves
-
Thiiranes are obtained in excellent yields and with high diastereoselectivity upon microwave irradiation of a mixture of α-haloketones, O,O-diethyl hydrogen phosphorodithioate and alumina-supported sodium borohydride in solvent-free conditions.
- Yadav, Lal Dhar S.,Kapoor, Ritu
-
-
Read Online
- Precise Synthesis of Poly(thioester)s with Diverse Structures by Copolymerization of Cyclic Thioanhydrides and Episulfides Mediated by Organic Ammonium Salts
-
The precise synthesis of poly(thioester)s with diverse structures is still a significant challenge in the polymeric materials field. Herein, we report a novel approach to the synthesis of well-defined poly(thioester)s by the controlled alternating copolymerization of cyclic thioanhydrides and episulfides induced by simple organic ammonium salts. Both the cation and anion have strong effects on the copolymerization. [PPN]OAc ([PPN]=bis(triphenylphosphine)iminium) with a bulky cation was proven to be efficient in initiating this polymerization, yielding poly(thioester)s with a completely alternating structure, controlled molecular weight, and narrow polydispersity. The poly(thioester) obtained from succinic thioanhydride and propylene sulfide is a typical semicrystalline material, possessing a high refractive index of up to 1.78. Because it uses readily available monomers, this method is expected to open up a new route to poly(thioester)s with diverse structures and properties.
- Yue, Tian-Jun,Zhang, Ming-Chao,Gu, Ge-Ge,Wang, Li-Yang,Ren, Wei-Min,Lu, Xiao-Bing
-
-
Read Online
- Selective Conversion of 2-Mercaptoalkanols to Thiirans with Orthocarbonates
-
Tetraalkyl orthocarbonates 1 were demonstrated to serve as potent cyclodehydrating agents for 2-mercaptoalkanols 2 to give the corresponding thiirans in good yields in acid-catalyzed reactions in aprotic solvents.Effect of catalysts, solvents, and alkyl substituents of 1 were examined.Activity of the acid catalysts depended on their acidity (pKa), and the strong Lewis acid BF3*OEt2 also had high catalytic activity.Effects of solvents and alkyl substituents of 1 were little observed.
- Takata, Toshizaku,Endo, Takeshi
-
-
Read Online
- Cerium(IV) catalysis: Efficient conversion of epoxides to thiiranes
-
Cerium(IV) as ceric ammonium nitrate (CAN), catalyzes the conversion of different epoxides to their corresponding thiiranes in excellent yields. The reaction occurs efficiently in the presence of ammonium thiocyanate in tert-butanol at room temperature.
- Iranpoor,Kazemi
-
-
Read Online
- Stereospecific formation of S(-) styrene sulfide: Efficient conversion of epoxides to thiiranes catalysed with Ru(III)
-
Ru(III) catalysis the efficient conversion of different epoxides to their corresponding thiiranes in the presence of ammonium thiocyanate in excellent yields, Stereospecific conversion of R(+) styrene oxide to S(-) styrene sulfide was achieved in high optical purity.
- Iranpoor, Nasser,Kazemi, Foad
-
-
Read Online
- Low generation PAMAM-based nanomicelles as ROS-responsive gene vectors with enhanced transfection efficacy and reduced cytotoxicity: in vitro
-
Poly(amidoamine)s (PAMAMs) of high-generations (G > 5) exhibit high efficacy in gene transfection, but their high cost and severe cytotoxicity limit their use in biomedicine. In contrast, PAMAMs of low-generations (G w = 3500 Da) via disulfide bonds. This amphiphilic conjugate can self-assemble into stable nanomicelles. The results show that the obtained nanomicelles have a high zeta potential, which can condense DNA tightly. Moreover, the DNA/nanomicelle polyplexes can be fully dissociated by intracellular ROS and easily release the entrapped DNA. As gene vectors, the nanomicelles exhibited high transfection efficacy and fairly low cytotoxicity in vitro.
- Xu, Chen-Tao,Chen, Guang,Nie, Xuan,Wang, Long-Hai,Ding, Sheng-Gang,You, Ye-Zi
-
supporting information
p. 3273 - 3279
(2017/07/12)
-
- Silica chloride-catalyzed synthesis of thiiranes from oxiranes under solvent-free conditions
-
A mild, simple, and efficient method for the synthesis of thiiranes from epoxides using a catalytic amount of silica chloride under solvent-free conditions has been developed. Experimental simplicity, simple work-up procedure, and solvent-free reaction conditions are important features of the present protocol. Copyright Taylor & Francis Group, LLC.
- Wu, Liqiang,Yang, Limin,Fang, Lizhen,Yang, Chunguang,Yan, Fulin
-
experimental part
p. 2159 - 2164
(2010/11/19)
-
- Isolation of the key intermediates in the catalyst-free conversion of oxiranes to thiiranes in water at ambient temperature
-
Herein we shed light on the mechanism of the reaction of epoxides with ammonium thiocyanate to give the corresponding thiiranes in water, and we present a computational mechanistic model for this highly useful reaction.
- Kleiner, Christian M.,Horst, Luise,Wuertele, Christian,Wende, Raffael,Schreiner, Peter R.
-
supporting information; experimental part
p. 1397 - 1403
(2009/12/04)
-
- 2,4,6-Trichloro-1,3,5-triazine catalyzed synthesis of thiiranes from oxiranes under solvent-free and mild conditions
-
A simple, mild and efficient method has been developed for the synthesis of thiiranes from epoxides using a catalytic amount of 2,4,6-trichloro-1,3,5-triazine under solvent-free conditions.
- Bandgar,Joshi, Neeta S.,Kamble
-
p. 4775 - 4777
(2007/10/03)
-
- Synthesis and properties of alkoxy-substituted 1-aminopropane-2-thiols
-
A series of alkoxy and alkyl derivatives of 1-aminopropane-2-thiols ROCH2CH(SH)CH2NR1R2 and 1 have been prepared by nucleophilic opening of thiiranes by secondary and primary amines.These compounds have also been prepared as hydrochlorides ROCH2CH(SH)CH2NR1R2*HCl andNR1*HCl.The structures of the synthesized compounds have been proved by IR and 1H NMR spectroscopy.Antimicrobial activities of the compounds have been examined.
- Allakhverdiev, M. A.,Farzaliev, V. M.,Guseinova, T. M.,Kerimov, V. M.,Magerramov, A. M.
-
p. 1641 - 1644
(2007/10/03)
-
- DIOXYPHOSPHORANES, AN EMERGING CLASS OF VERSATILE REAGENTS FOR ORGANIC SYNTHESIS
-
Several ?-dioxyphosphoranes have been prepared and their structural characterizations using NMR techniques support the trigonal bipyramidal conformer as the most stable for the acyclic phosphoranes.Their utility in smooth conversions of hydroxylated substrates to the corresponding X-heterocycles is documented.
- Kelly, Jeffery W.,Robinson, Philip L.,Evans, Slayton A.
-
p. 147 - 150
(2007/10/02)
-
- Pesticidal compositions containing phosphoric esters and divalent sulphur compounds
-
Pesticidal composition comprising: a pesticidal, phosphoric ester the molecule of which has at least one alkyl group of 1 to 3 carbon atoms, 0.05 to 10% of an agent stabilizing the said ester against decomposition by protonisation, together with adjuvants characterized in that the stabilizing agent comprises at least one sulphur compound containing per molecule at least one divalent sulphur atom of which one valence is bonded to an atom chosen from sulphur, carbon, nitrogen, hydrogen, and metals capable of giving a salt, the other valence being bonded to an atom chosen from hydrogen, the carbon atom already noted, a second carbon atom, the nitrogen atom already noted, a second nitrogen atom, the metal atom already noted in the case of a metal of valence greater than one, a second atom of metal and oxygen when the first valence is not attached to an atom of hydrogen, the proportion of sulphur calculated with reference to the weight of the sulphur compound being between 5 and 99%. Process for stabilizing a phosphoric ester of which the molecule possesses at least one alkyl group containing 1 to 3 carbon atoms characterized in that there is added to the phosphoric ester or to a mixture which contains it, 0.05 to 10% calculated on the weight of the phosphoric acid ester of an agent capable of stabilizing the said phosphoric ester against protonisation and comprising at least one sulphur compound such as that defined thereupon.
- -
-
-