- Ring Expansion of Thiolactams via Imide Intermediates: An Amino Acid Insertion Strategy
-
The AgI-promoted reaction of thiolactams with N-Boc amino acids yields an N-(α-aminoacyl) lactam that can rearrange through an acyl transfer process. Boc-deprotection results in convergence to the ring-expanded adduct, thereby facilitating an overall insertion of an amino acid into the thioamide bond to generate medium-sized heterocycles. Application to the site-specific insertion of amino acids into cyclic peptides is demonstrated.
- Shang, Jing,Thombare, Varsha J.,Charron, Carlie L.,Wille, Uta,Hutton, Craig A.
-
supporting information
p. 1620 - 1625
(2020/12/23)
-
- Amide (A)–thioamide (T) interconversions using Ph3SiSH (A to T) and Ph3SnOH (T to A) reagents
-
Ph3SiSH transforms amides to thioamides and Ph3SnOH performs the reverse process, with the concomitant formation of Ph3SiOH (or Ph3SiOSiPh3) and Ph3SnSSnPh3, respectively. The chemistry is a delightful illustration of the oxophilicity of silicon compared to the thiophilicity of tin and occurs under relatively mild conditions, and for amide to thioamide transformation requires no amide activation. The chemistry is in accord with available data for Si?(S)(O), Sn?(O)(S) and C?(O)(S) bond energies. Copyright
- Arias-Ugarte, Renzo N,Sharma, Hemant K,Pannell, Keith H
-
p. 510 - 513
(2016/07/16)
-
- An Aluminum(III)-Catalyzed Thioamide-Aldehyde-Styrene Condensation: Direct Synthesis of Allylic Thioamide Derivatives
-
An aluminum(III) triflate catalyzed three-component synthesis of allylic thioamide derivatives by condensation of a thioamide, paraformaldehyde and a styrene is reported.
- Xu, Bin,Zhong, Xue,Wang, Xi-Cun,Quan, Zheng-Jun
-
supporting information
p. 2237 - 2240
(2016/11/07)
-
- O,O-Diethyl dithiophosphoric acid mediated direct synthesis of thioamides from aldehydes and ketones
-
A general and convenient method for a one-pot conversion of aldehydes and ketones into thioamides has been developed. The protocol involves oximation of aldehydes and ketones followed by deoxygenative thioamidation of oximes with O,O-diethyl dithiophosphoric acid which acts as an acid as well a source of sulfur. The method is operationally simple, high yielding, and also applicable to the conversion of amides and nitriles into the corresponding thioamides.
- Yadav, Arvind K.,Srivastava, Vishnu P.,Yadav, Lal Dhar S.
-
p. 7113 - 7116
(2013/01/15)
-
- Facile synthesis of thioamides via P2S5-mediated beckmann rearrangement of oximes
-
A facile and efficient approach to the synthesis of secondary thioamides from ketoximes via Beckmann rearrangement has been established, using phosphorus pentasulfide as a dehydrating and thiating agent. It is also efficient for the preparation of primary thiobenzamide from benzaldoxime. This approach features simple-operation, easy-control and good to excellent yields.
- Li, Jiangsheng,Cheng, Chao,Zhang, Xinrui,Li, Zhiwei,Cai, Feifei,Xue, Yuan,Liu, Weidong
-
p. 1687 - 1689
(2012/10/29)
-
- A THIONATION PROCESS AND A THIONATING AGENT
-
A process for transforming a group >C=O (I) in a compound into a group >C=S (II) or into a tautomeric form of group (II) in a reaction giving a thionated reaction product, by use of crystalline P2S5·2 C5H5N as a thionating agent. A thionating agent which is crystalline P2S5·2 C5H5N
- -
-
Page/Page column 12
(2012/08/27)
-
- A thionation process and a thionating agent
-
A process for transforming a group >C=O (I) in a compound into a group >C=S (II) or into a tautomeric form of group (II) in a reaction giving a thionated reaction product, by use of crystalline P2S5·2 C5H5N as a thionating agent. A thionating agent which is crystalline P2S5·2 C5H5N.
- -
-
Page/Page column 8
(2012/08/14)
-
- Facile and odorless one-pot process for the synthesis of N-substituted thioamides via TsCl-mediated Beckmann rearrangement of ketoximes
-
A facile and odorless one-pot thionation process for the synthesis of N-substituted thioamides using chemically stable and inexpensive thiourea reagent via the Beckmann rearrangement of ketoximes, has been described. Georg Thieme Verlag Stuttgart · New York.
- Liu, Li-Feng,An, Na,Pi, Hong-Jun,Ying, Jun,Du, Wenting,Deng, Wei-Ping
-
supporting information; experimental part
p. 979 - 981
(2011/06/11)
-
- Thionations using a P4S10-pyridine complex in solvents such as acetonitrile and dimethyl sulfone
-
Tetraphosphorus decasulfide (P4S10) in pyridine has been used as a thionating agent for a long period of time. The moisture-sensitive reagent has now been isolated in crystalline form, and the detailed structure has been determined by X-ray crystallography. The thionating power of this storable reagent has been studied and transferred to solvents such as acetonitrile in which it has proven to be synthetically useful and exceptionally selective. Its properties have been compared with the so-called Lawesson reagent (LR). Particularly interesting are the results from thionations at relatively high temperatures (165 °C) in dimethyl sulfone as solvent. Under these conditions, for instance, acridone and 3-acetylindole could quickly be transformed to the corresponding thionated derivatives. Glycylglycine similarly gave piperazinedithione. At these temperatures, LR is inefficient due to rapid decomposition. The thionated products are generally cleaner and more easy to obtain because in the crystalline reagent, impurities which invariably are present in the conventional reagents, P4S 10 in pyridine or LR, have been removed. 2011 American Chemical Society.
- Bergman, Jan,Pettersson, Birgitta,Hasimbegovic, Vedran,Svensson, Per H.
-
supporting information; experimental part
p. 1546 - 1553
(2011/06/11)
-
- Targeting the polyamine transport system with benzazepine- and azepine-polyamine conjugates
-
The polyamine transport system (PTS) whose activity is up-regulated in cancer cells is an attractive target for drug design. Two heterocyclic (azepine and benzazepine) systems were conjugated to various polyamine moieties through an amidine bound to afford 18 compounds which were evaluated for their affinity for the PTS and their ability to use the PTS for cell delivery. Structure-activity relationship studies and lead optimization afforded two attractive PTS targeting compounds. The azepine-spermidine conjugate 14 is a very selective substrate of the PTS that may serve as a vector for radioelements used for diagnoses or therapeutics in nuclear medicine. The nitrobenzazepine-spermine conjugate 28 is a very powerful PTS inhibitor with very low intrinsic cytotoxicity, able to prevent the growth of polyamine depleted cells in presence of exogenous polyamines.
- Tomasi, Sophie,Renault, Jacques,Martin, Bénédicte,Duhieu, Stephane,Cerec, Virginie,Le Roch, Myriam,Uriac, Philippe,Delcros, Jean-Guy
-
experimental part
p. 7647 - 7663
(2011/02/22)
-
- Ketoximes to N-substituted thioamides via PSCl3 mediated Beckmann rearrangement
-
N-Substituted thioamides were accessed from ketoximes by utilising PSCl3 as a uniquely capable reagent to induce Beckmann rearrangement as well as to capture the intermediate nitrilium ion. The Royal Society of Chemistry 2009.
- Pathak, Uma,Pandey, Lokesh Kumar,Mathur, Sweta,Suryanarayana
-
scheme or table
p. 5409 - 5411
(2009/12/08)
-
- Direct thionation and selenation of amides using elemental sulfur and selenium and hydrochlorosilanes in the presence of amines
-
Reactions of amides with elemental sulfur in the presence of hydrochlorosilanes and amines give the corresponding thioamides in good to high yields. The process takes place via reduction of elemental sulfur by the hydrochlorosilane in the presence of a suitable amine. The methodology can be applied to the selenation of amides by using elemental selenium. Thlonation and selenation of an acetyl-protected sialic acid derivative are found to take place selectively at the amide group.
- Shibahara, Fumitoshi,Sugiura, Rie,Murai, Toshiaki
-
supporting information; experimental part
p. 3064 - 3067
(2009/12/05)
-
- Synthesis and application of a fluorous Lawesson's reagent: Convenient chromatography-free product purification
-
A fluorous analogue of Lawesson's reagent for thionation of carbonyl compounds has been developed and its use demonstrated on a series of amides, esters, and ketones. The separation of the Lawesson's reagent-derived byproducts can be achieved by a simple fluorous solid-phase extraction.
- Kaleta, Zoltan,Tarkanyi, Gabor,Goemoery, Agnes,Kalman, Ferenc,Nagy, Tamas,Soos, Tibor
-
p. 1093 - 1095
(2007/10/03)
-
- Synthesis of ω-aminodithioesters
-
ω-Aminodithioester derivatives were obtained from thionolactams by reaction with an alkyl triflate followed by thiolysis with hydrogen sulfide. The presence of an electron-withdrawing group was required on the N1 position (p-nitrophenyl or benzoyl) to favor the ring opening of γ-, δ- and ε-thionolactams. In the case of β-thionolactam, activation was provided by a CF2 motif in C3 position. Georg Thieme Verlag Stuttgart.
- Lacroix, Simon,Rixhon, Vinciane,Marchand-Brynaert, Jacqueline
-
p. 2327 - 2334
(2008/02/03)
-
- Silver-catalyzed hydroamination: Synthesis of N-bridgehead pyrroles, incorporating a protection-deprotection strategy for preparation of cyclic secondary vinylogous carbamates
-
N-Bridgehead pyrroles are efficiently prepared from cyclic secondary vinylogous carbamates using a two-step sequence. This sequence involves C-propargylation followed by a silver-catalyzed intramolecular hydroamination. Hydroamination is brought about using microwave irradiation and affords the desired N-bridgehead pyrroles rapidly and in good yield. Cyclic secondary vinylogous carbamates are prepared using a mild, economical procedure. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Robinson, Ross S.,Dovey, Martin C.,Gravestock, David
-
p. 505 - 511
(2007/10/03)
-
- Thionation with the reagent combination of phosphorus pentasulfide and hexamethyldisiloxane
-
The combination of P4S10 and hexamethyldisiloxane efficiently converts esters, lactones, amides, lactams, and ketones to their corresponding thiono derivatives. In the presence of elemental sulfur, 3-oxoesters are converted to dithiolethiones by this reagent. Yields are comparable to or superior to those obtained with Lawesson's reagent. The method has the advantage that reagent-derived byproducts may be removed by a simple hydrolytic workup or by filtration through silica gel, rather than by chromatography, as required for Lawesson's reagent.
- Curphey, Thomas J.
-
p. 6461 - 6473
(2007/10/03)
-
- A polymer-supported thionating reagent
-
A new polymer-supported reagent for the conversion of carbonyls to thiocarbonyls has been developed and its use demonstrated on a range of amides. Secondary or tertiary amides are converted cleanly and efficiently through to the corresponding thioamides and primary amides are converted to the corresponding nitriles. The reactions can be facilitated by conventional heating. However, if microwave heating is used, in the presence of an ionic liquid, enhanced reaction rates are achieved.
- Ley, Steven V.,Leach, Andrew G.,Storer, R.Ian
-
p. 358 - 361
(2007/10/03)
-
- Microwave-accelerated solvent-free synthesis of thioketones, thiolactones, thioamides, thionoesters, and thioflavonoids
-
Formula presented An expeditious, solvent-free, and high yield conversion of ketones, flavones, isoflavones, lactones, amides, and esters to the corresponding thio analogues is described utilizing Lawesson's reagent in a process that circumvents the use of dry solvents and excess of the reagent.
- Varma, Rajender S.,Kumar, Dalip
-
p. 697 - 700
(2008/02/11)
-
- Reaction of lactim ethers and lactim sulfides with electrophiles: Attack at nitrogen followed by ring-opening under neutral conditions
-
Electrophilic push-pull molecules react at the nitrogen of lactim ethers and lactim sulfides; subsequent hydrolysis gives ring-opened products in good yields.
- Anbazhagan, Mariappan,Dixit, Arun N.,Rajappa, Srinivasachari
-
p. 2421 - 2424
(2007/10/03)
-
- 8H-ANHYDRO-4-HYDROXY-2-OXO-1,3-THIAZINUM HYDROXIDES AS MESOIONIC 1,4-DIPOLES
-
The previously unknown 8H-anhydro-4-hydroxy-2-oxo-1,3-thiazinum hydroxides (1) were prepared and their 1,4-dipolar cycloaddition behavior was examined.In most cases, elimination of the proton in the 8-position of the mesoionic ring was observed to occur unless extremely reactive dipolarophiles were used.The S,N-ketene acetals were converted to the corresponding α-diazo ketones for further study.
- Padwa, Albert,Coats, Steven J.,Hadjiarapoglou, Lazaros
-
p. 1631 - 1652
(2007/10/03)
-
- 8H-Anhydro-4-hydroxy-2-oxo-1,3-thiazinium Hydroxides as mesoionic 1,4-Dipoles
-
The previously unknown 8H-anhydro-4-hydroxy-2-oxo-1,3-thiazinium hydroxides (1) were prepared and their 1,4-dipolar cycloaddition behavior was examined.In most cases, elimination of the proton in the 8-position of the mesoionic ring was observed to occur unless extremely reactive dipolarophiles were used.The S,N-ketene acetals were converted to the corresponding α-diazo ketones for further study.
- Padwa, Albert,Coats, Steven J.,Hadjiarapoglou, Lazaros
-
p. 219 - 242
(2007/10/02)
-
- Transformation of Alkyl N-(Vinyloxy)benzimidates to Alkyloxazoles. Mechanism and Extension
-
Transformation of alkyl N-(vinyloxy)benzimidates to alkyloxazoles proceeds through the intermediates: a charge-separated 1,2-oxazetidine derivative and then 1-hydroxy-2-imino>maleic acid diester, while their photochemical transformation takes place via a concerted sigmatropic shift.As the extension of this reaction, the preparation of the precursor proposed for virginiamycin M2 synthesis and the reaction of N-analogs of alkyl N-(vinyloxy)benzimidates are described.
- Yokoyama, Masataka,Menjo, Yasuhiro,Ubukata, Makoto,Irie, Masakazu,Watanabe, Mikari,Togo, Hideo
-
p. 2219 - 2226
(2007/10/02)
-
- Diethylborylierung und Sulfidierung von ω-Lactamen
-
Several reaction modes of ω-lactams with Et3B are observed between 20 and 110 deg C.The Et2B lactims (1) having various degrees of association x; 1b; (1d)2 (X-ray structure); 1e; (1f)4> are formed by elimination of 1 mol of ethane.The condensation products result by elimination of 1.33 mol of ethane together with the lactim derivatives (3b; 3c).Thermolysis (>125 deg C) of (1d)2, 1e, and (1f)4 leads to mixtures, in which the compounds 2d, e,f and 3d, e, f, resp., have been identified (NMR, MS).Differences of the thermal behaviour of 1a-f (s-cis/trans conformers, cis/trans lactims, association degree) are discussed. - From 2b,c and Hacac the N-acylamidines (4b,c) are obtained, which react with (9-BBN)2S to yield the monomeric 9-BBN-ω-thiolactims .The latter react with MeOH to give the ω-thiolactams (6b,c) and 9-MeO-9-BBN, from which the 2:2 MeOH addition compound (7)2 (X-ray structure) is obtained. Key Words: ω-Lactimes, boryl derivatives of/ω-Lactimes, condensation of/Amidines, N-acyl, borylsulfoboration of/ω-Tholactims, 9-BBN derivatives of/ω-Thiolactimes.
- Koester, Roland,Kucznierz, Ralf,Schuessler, Wilhelm,Blaeser, Dieter,Boese, Roland
-
p. 189 - 200
(2007/10/02)
-
- In Situ Reagent for Thionation of Amides, Peptides and Lactams
-
An in situ reagent 1A for thionation of amides, peptides and lactams is prepared from phosphorus decasulfide/sodium carbonate (1:1 ratio) in THF at 25 deg C.
- Brillon, Denis
-
p. 3085 - 3095
(2007/10/02)
-
- Reaction of Phosphorus Pentasulfide with Organolithiums. An In Situ Reagent for the Preparation of Thiolactams
-
Phosphorus pentasulfide reacts under mild conditions with four equivalents of n-butyllithium, methyllithium or phenyllithium giving solutions in tetrahydrofuran.The new reagents in situ convert lactams to thiolactams and show significant selectivity in the type of reactive lactams.
- Goel, O. P.,Krolls, U.
-
p. 162 - 164
(2007/10/02)
-
- STUDIES ON ORGANOPHOSPHORUS COMPOUNDS XLVII PREPARATION OF THIATED SYNTHONS OF AMIDES, LACTAMS AND IMIDES BY USE OF SOME NEW P,S-CONTAINING REAGENTS
-
The thionation properties of 2,4-bismethylthio-1,3,2,4-dithiadiphosphetane 2,4-disulfide, 1, 2,4-bis(4-phenoxyphenyl)-1,3,2,4-dithiaphosphetane 2,4-disulfide, 2, 2,4-bis(4-phenylthiophenyl)-1,3,2,4-dithiaphosphetane 2,4-disulfide, 3, and 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiaphosphetane 2,4-disulfide (LR), 4, have been investigated on a series of amides, lactams and imides.The most remarkable feature is that 2, 3 and 4 thionate most amides and lactams in THF at room temperature (reaction time 5 min) to give the corresponding thionated compounds.Imides are easily thionated by 2, 3 and 4 in DME at 60 oC.The reactions of 1 with amides, imides and most lactams are run at 60 oC to give good yields of the corresponding thionated compounds.
- Yde, B.,Yousif, N. M.,Pedersen, U.,Thomsen, I.,Lawesson, S. -O.
-
p. 2047 - 2052
(2007/10/02)
-