- Polymer-supported thiocyanate as new, versatile and efficient polymeric reagent for conversion of alkyl halides to corresponding alkyl thiocyanates under mild conditions
-
Crosslinked poly(N-methyl-4-vinylpyridinium)thiocyanate [P 4-Me]SCN (II) is prepared easily and is used as a new polymeric reagent for synthesis of alkyl thiocyanates from alkyl halides under mild and nonaqueous conditions. The used polymeric reagent usually can be removing quantitatively and be regenerated.
- Zarchi, Mohammad Ali Karimi
-
-
Read Online
- AIBN-initiated direct thiocyanation of benzylic sp3C-H with: N -thiocyanatosaccharin
-
Direct thiocyanations of benzylic compounds have been implemented. Here, a new strategy, involving a free radical reaction pathway initiated by AIBN, was used to construct the benzylic sp3 C-SCN bond. In this way, the disadvantage of other strategies involving introducing leaving groups in advance to synthesize benzyl thiocyanate compounds was overcome. The currently developed protocol also involved the use of readily available raw materials and resulted in high product yields (up to 100%), both being great advantages for synthesizing benzyl thiocyanates.
- Wu, Di,Duan, Yongjie,Liang, Kun,Yin, Hongquan,Chen, Fu-Xue
-
supporting information
p. 9938 - 9941
(2021/10/12)
-
- Synthesis of alkyl thiocyanates from alcohols using a polymer-supported thiocyanate ion promoted by cyanuric chloride/dimethylformamide
-
A convenient procedure for one-pot conversion of alcohols into the corresponding alkyl thiocyanates in the presence of cross-linked poly (N-propyl-4-vinylpyridinium) thiocyanate ion [P4-VP]Pr-SCN, promoted by cyanuric chloride/dimethylformamide, is described. Various alcohols were converted to their corresponding alkyl thiocyanates and it was observed that substituted benzyl alcohol with electron-withdrawing or electron-donating groups were transformed into the corresponding benzyl thiocyanate derivatives in high to excellent yields in a short reaction time but, sterically hindered alcohols produced the corresponding thiocyanates in very low yields.
- Karimi Zarchi, Mohammad Ali,Tabatabaei Bafghi, Asmaosadat
-
p. 403 - 412
(2015/06/22)
-
- Phosphine-free conversion of alcohols into alkyl thiocyanates using trichloroisocyanuric acid/NH4SCN
-
A convenient and efficient phosphine-free procedure for the one-pot conversion of primary, secondary and tertiary alcohols into the corresponding alkyl thiocyanates or alkyl isothiocyanates is described using trichloroisocyanuric acid/NH4SCN.
- Azadi, Roya,Mokhtari, Babak,Makaremi, Mohamad-Ali
-
experimental part
p. 77 - 80
(2012/03/26)
-
- Selectfluor F-TEDA-BF4 mediated thiocyanation or isothiocyanation of alcohols by in situ generation of [+SCN] under heterogeneous and neutral conditions
-
A convenient approach for thiocyanation of alcohols has been developed using ammonium thiocyanate as thiocyanating agent in the presence of a catalytic amount of Selectfluor F-TEDA-BF4 in aqueous acetonitrile. In this method various alcohols generally afforded the corresponding thiocyanates or isothiocyanates directly in good to high yield under heterogeneous and neutral conditions.
- Khazaei, Ardeshir,Rahmati, Sadegh,Khalafi-Nezhad, Ali,Saednia, Shahnaz
-
experimental part
p. 123 - 125
(2012/05/05)
-
- Heterogeneous thiocyanation of benzylic alcohols and silyl and THP ethers, and deprotection of silyl and THP-ethers by [PCl3-n(SiO 2)n] (silphos)
-
Silicaphosphite (silphos), [PCl3-n(SiO2) n], as a heterogeneous phosphorous compound, catalyzes the thiocyanation of benzylic alcohols and silyl and THP ethers in the presence of I2 and NH4SCN in refluxing CH3CN. The produced silphos oxide byproduct can be easily separated by a simple filtration. Silphos is also used for the efficient and selective deprotection of silyl and THP-ethers to their corresponding alcohols. Copyright
- Iranpoor,Firouzabadi,Bahador,Jamalian
-
experimental part
p. 1972 - 1978
(2010/11/16)
-
- In situ-generated N-thiocyanatosuccinimide (NTS) as a highly efficient reagent for the one-pot thiocyanation or isothiocyanation of alcohols
-
The first application of in situ-generated N-thiocyanatosuccinimide (NTS) for the thiocyanation of alcohols is described. This method can be easily applied for the facile conversion of primary, secondary and tertiary alcohols into the corresponding alkyl thiocyanates or alkyl isothiocyanates in good to excellent yields.
- Mokhtari, Babak,Azadi, Roya,Rahmani-Nezhad, Samira
-
experimental part
p. 6588 - 6589
(2011/02/21)
-
- Niobium(V) pentachloride: an efficient catalyst for C-, N-, O-, and S-nucleophilic substitution reactions of benzylic alcohols
-
Benzylic alcohols undergo easy C-, N-, O-, and S- centered nucleophilic substitution reactions with a catalytic amount of NbCl5.
- Yadav,Bhunia, Dinesh C.,Vamshi Krishna,Srihari
-
p. 8306 - 8310
(2008/03/30)
-
- A new diphenylphosphinite ionic liquid (IL-OPPh2) as reagent and solvent for highly selective bromination, thiocyanation or isothiocyanation of alcohols and trimethylsilyl and tetrahydropyranyl ethers
-
A new diphenylphosphinite ionic liquid (IL-OPPh2) is introduced. This ionic liquid is used as both a reagent and a solvent to convert alcohols and trimethylsilyl and tetrahydropyranyl (THP) ethers into their corresponding alkyl bromides, thiocyanates or isothiocyanates in the presence of Br2 and SCN- at 80 °C. In this ionic liquid, bromination and thiocyanation of alcohols occurs highly selectively in the presence of trimethylsilyl and THP-ethers and also between different classes of alcohols. The use of this ionic liquid allows easy separation of the desired products from the phosphinate by-product.
- Iranpoor, Nasser,Firouzabadi, Habib,Azadi, Roya
-
p. 5531 - 5534
(2007/10/03)
-
- Preparation of thiocyanates and isothiocyanates from alcohols, thiols, trimethylsilyl-, and tetrahydropyranyl ethers using triphenylphosphine/2,3-dichloro-5,6-dicyanobenzoquinone (DDQ)/n-Bu4NSCN system
-
A combination of triphenylphosphine (PPh3) and 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) provides a safe and easily available mixed reagent system for the conversion of 1° and 2° alcohols, thiols, trimethylsilyl-, and tetrahydropyranyl ethers to their corresponding thiocyanates and the 3° ones to isothiocyanates in good to high yields.
- Iranpoor, Nasser,Firouzabadi, Habib,Nowrouzi, Najmeh
-
p. 5498 - 5501
(2007/10/03)
-
- Efficient conversion of tetrahydropyranyl (THP) ethers to their corresponding thiocyanates with in-situ-generated Ph3P(SCN) 2
-
Immediate and efficient one-pot conversion of tetrahydropyranyl (THP) ethers to their corresponding thiocyanates by in-situ-generated Ph 3P(SCN)2 is described. Primary and secondary alkyls and also benzylic THP ethers are converted to their corresponding thiocyanates in excellent yields at room temperature by this method. Copyright Taylor & Francis Inc.
- Iranpoor, Nasser,Firouzabadi, Habib,Shaterian, Hamid Reza
-
p. 2093 - 2096
(2007/10/03)
-
- Conversion of Alcohols, Thiols, Carboxylic Acids, Trimethylsilyl Ethers, and Carboxylates to Thiocyanates with Triphenylphosphine/ Diethylazodicarboxylate/NH4SCN
-
A novel and highly selective method is described using triphenylphosphine/ diethylazodicarboxylate (DEAD)/NH4SCN for the conversion of alcohols, thiols, carboxylic acids, silyl ethers, and silyl carboxylates to their corresponding thiocyanates.
- Iranpoor, Nasser,Firouzabadi, Habib,Akhlaghinia, Batool,Azadi, Roya
-
-
- Efficient conversion of silyl ethers to thiocyanates with Ph3P(SCN)2
-
A new and efficient method for the conversion of primary and secondary alkyl, aryl, allyl and benzyl silyl ethers to their corresponding thiocyanates by in-situ generation of Ph3P(SCN)2 is described. The reactions occur immediately at room temperature and provide high to excellent yields of thiocyantes.
- Iranpoor,Firouzabadi,Shaterian
-
-
- Efficient one-pot thiocyanation of primary, secondary and tertiary alcohols by in situ generation of Ph3P(SCN)2. A modified procedure
-
The preparation of Ph3P(SCN)2 is modified by using a combination of Ph3P, NH4SCN and Br2 at room temperature for the efficient conversion of primary, secondary and tertiary alcohols to their corresponding thiocyanates in excellent yields.
- Iranpoor,Firouzabadi,Shaterian
-
p. 676 - 677
(2007/10/03)
-
- Kinetics of the reactions of laser-flash photolytically generated carbenium ions with alkyl and silyl enol ethers. Comparison with the reactivity toward alkenes, allylsilanes and alcohols
-
Diarylcarbenium ions (benzhydryl cations) are generated from diarylmethyl chlorides by 20-ns laser pulses (248 nm) in acetonitrile solution at 20°C. The second-order rate constants for their reactions with n- and π-nucleophiles (anions, alcohols, water, alkenes, allylsilanes, alkyl and silyl enol ethers) are determined by monitoring the decay of the UV-vis transients at variable nueleophile concentrations. Only reactive nucleophiles (k2 > 106-107 L mol-1 s-1) can be investigated by this method because of the concomitant reactions of the carbenium ions with the solvent acetonitrile and the chloride ions in produced in the photoheterolysis. The largest observed values of k2 are ~2 × 1010 for reactions with anions and (2-4) × 109 L mol-1 s-1 for reactions with neutral nucleophiles. Alkoxy-substituted ethylenes are 300-105 times more reactive than the corresponding alkyl-substituted ethylenes. The reactivities of structurally analogous alkyl and silyl enol ethers differ by less than 1 order of magnitude. In sharp contrast to the situation previously observed for the reactions of benzhydryl cations with alkenes, the nucleophilic reactivities of the enol ethers correlate with their ionization potentials and not with the stabilities of the carbenium ions produced in the rate-determining step. The rate constants measured for the reactions of the flash photolytically generated benzhydryl cations with alkenes and allylsilanes agree well with those extrapolated from the reactivities of these nucleophiles toward less electrophilic benzhydryl cations, which have previously been determined by conventional techniques. Combination of the two sets of data yields a nucleophilicity scale with respect to the reference electrophile (p-H3CC6H4)2CH+.
- Bartl, J?rg,Steenken, Steen,Mayr, Herbert
-
p. 7710 - 7716
(2007/10/02)
-
- Nucleophilic Substitution Reactions of Alkyl Halides By Using New Polymer-Supported Reagents Containing Hemin
-
A new polymer reagent consisting of hemin, divinylbenzene, and 2-methyl-5-vinylpyridine was synthesized by suspension copolymerization.Substitution reactions of primary, secondary, and tertiary alkyl halides with the hemin copolymer combined with cyanide, azide, and thiocyanate ions were given satisfactory yields.This reaction mechanism was revealed to be a SNi type on the basis of stereochemical study.The hemin copolymer was not only a polymer-supported reagent with functional capabilities, but also served to separate the product from the reaction mixture.
- Saito, Kiyoshi,Harada, Kaoru
-
p. 2562 - 2566
(2007/10/02)
-