A highly regio and stereocontrolled procedure for the synthesis of vinyl dithiocarbamates via catalystfree hydrothiolation of unactivated alkynes with in situ prepared dithiocarbamic acids with total atom economy is reported. In quest of stereoselective switch for onwater hydrothiolation of terminal alkynes using different additives and green synthesis of vicinal dithioethers. While unactivated terminal alkynes afforded the markovnikov adducts with excellent regioselectivity. Alkyne hydrothiolation that is, the addition of the sh bond of a thiol. Stereoselective hydrothiolation of alkynes catalyzed by. Pdf catalytic alkyne hydrothiolation with alkanethiols.
Hydroborationoxidation of alkynes video khan academy. The preparations of alkynes are very similar to those of the alkenes. The hydrothiolation of alkenes or alkynes with thiols, represents an attractive and atom economic approach for the formation of cs bonds. With regard to the mechanism of hydrothiolation of terminal alkynes in water, the literature reports are of different views. Aromatic alkynes yield corresponding 1alkenyl sulfides, whereas aliphatic alkynes undergo doubleaddition yielding vicinal disulfides in good to excellent yields. Aromatic alkynes yield corresponding alk enyl sul des, wher eas aliphatic alkynes undergo doubleaddition yielding vicinal disul des in good to excellent yields. Design of a nihcatalyzed remote hydrothiolation reaction. Research article in quest of stereoselective switch for on. Synthesis of 1,1disubstituted olefins via catalytic alkyne. Waterpromoted regioselective hydrothiolation of alkynes. However, a novel pdcatalyzed addition of thiols to alkenes bearing a heteroatom, such as oxygen and nitrogen, is found to proceed under mild conditions to give the corresponding markovnikov adducts, regioselectively, in good yields. The loss of a hydrogen atom and a halogen atom from adjacent alkane carbon atoms leads to the formation of an alkene. Calciumcatalyzed bishydrothiolation of unactivated. The reaction allows olefins or alkynes bearing various functional groups to react with different thiols, providing good to excellent yields of alkyl sulfides or vinyl sulfides.
In contrast, the formal analogous addition of ammonia or primary and secondary amines to nonactivated alkenes and alkynes scheme 1 does not have comparable significance. Organic chemistry international hindawi publishing corporation. Hydrothiolation using alkyl thiols proceeds with excellent regioselectivity, providing convenient access to branched alkyl vinyl sulfides, which are difficult to synthesize by other means. Department of material chemistry, graduate school of engineering, kyoto university, kyotodaigaku katsura, nishikyoku, kyoto 6158510, japan. Note that if a terminal alkyne is produced, the strong base will deprotonate the alkyne to form an alkynide anion.
Catalysed hydrofunctionalisation of alkenes and alkynes. Catalystfree hydrothiolation of alkynes with dithiocarbamic acids. In this context, water extract of rice straw ash wersa has been proven to be a green, mild and efficient solvent for the preparation of vinyl thioethers. Addition of thiols to alkynes is an efficient strategy for the synthesis of vinyl sulfides, which are valuable intermediates in synthetic organic chemistry for the. Regioselective hydrothiolation of alkenes bearing heteroatoms.
Highly regio and stereocontrolled synthesis of vinyl sulfides via transitionmetalcatalyzed hydrothiolation of alkynes with thiols akiya ogawa, takuma ikeda, kouichi kimura, and toshikazu hirao contribution from the department of applied chemistry, faculty of engineering, osaka university, suita, osaka 5650871, japan received november 16, 1998. Pdf in quest of stereoselective switch for onwater. Among hydrocarbons, alkynes have higher boiling point than alkenes and alkanes because of the presence of triple bond in alkynes. Abstract alkyne hydrothiolation that is, the addition of the sh bond of a. Rhodiumcatalyzed hydrothiolation of alkynes with thiols for. Indium iii catalyzed substrate selective hydrothiolation of terminal alkynes article in chemical communications 4833.
The simplest alkyne, ethyne also known as acetylene, has two carbon atoms and the. View the article pdf and any associated supplements and figures for a period of 48 hours. Organoactinidemediated hydrothiolation of terminal. Scribd is the worlds largest social reading and publishing site. However, a novel pdcatalyzed addition of thiols to alkenes bearing a heteroatom, such as oxygen and nitrogen, is found to proceed under mild conditions to give the corresponding markovnikov adducts, regioselectively. Here we report a cesiumcatalyzed hydrothiolation of alkynes.
Nickelcatalysed selective migratory hydrothiolation of. Hydrothiolation of alkenes and alkynes catalyzed by 3,4. Nickelcatalysed selective migratory hydrothiolation of alkenes and. The main preparative reactions involve the elimination of groups or ions from molecules, resulting in the formation of. These were used to catalyse the hydrothiolation of alkynes with a range. Facile access to z1alkenyl sulfides azusa kondoh, kazuaki takami, hideki yorimitsu, and koichiro oshima. In sharp contrast to many examples of transitionmetalcatalyzed hydrothiolation of alkynes, the corresponding catalytic addition of thiols to alkenes has remained undeveloped. Onwater hydrothiolation reaction between terminal alkyne and thiol has been probed in the presence of various additives. Indiumiiicatalyzed substrate selective hydrothiolation. Formation of 1alkenyl sulfides proceeds with a high degree of regioselectivity via antimarkovnikov addition. This group of compounds is a homologous series with the general molecular formula of c n h 2 n2, where n equals any integer greater than one. Simple alkynes are named much like alkenes, except the ending is changed fromane toyne. Alkynes are hydrocarbons with carboncarbon triple bonds.
Acetylene itself is formed from the reaction of the inorganic compound calcium carbide with water. The mechanisms of the goldcatalyzed hydrothiolation of alkynes and alkenes with phenthiol have been investigated using density functional theory calculations done at the b3lyp631gd, p sdd. Reactions that employ alkynes as starting materials are synthetically versatile, since alkynes can be prepared by a variety of strategies, including sonogashira coupling, nucleophilic addition of metal acetylides 14, and homologation of carbonyl groups 15. Catalystfree hydrothiolation of alkynes with dithiocarbamic. Hydrothiolation of unactivated alkynes catalyzed by indium. Catalytic alkyne hydrothiolation with alkanethiols using wilkinsons catalyst. In quest of stereoselective switch for onwater hydrothiolation of. Regio and stereoselective synthesis of vinyl sulfides via. Many regio and stereoselective modifications of related reactions are known.
Highly stereoselective antimarkovnikov hydrothiolation of alkynes. Atomefficient organoactinidecatalyzed intermolecular hydrothiolation of terminal alkynes is achieved by thiv and uiv complexes to yield vinyl sulfides. Alkynes hydrothiolation radical reactions click chemistry. The hydrothiolation of alkenes or alkynes with thiols represents an attractive and atom economical approach for the formation of cs bonds. A simple and efficient method for palladium and copper cocatalyzed markovnikov hydrothiolation of thiols to olefins or alkynes has been developed. Visible light initiated hydrothiolation of alkenes and. Avelino corma, camino gonzalezarellano, marta iglesias and felix sanchez, efficient synthesis of vinyl and alkyl sulfides via hydrothiolation of alkynes and electrondeficient olefins using soluble and heterogenized gold complexes catalysts, applied catalysis a. Recent advances in the hydrosilylation of alkynes emily a. Visible light initiated hydrothiolation of alkenes and alkynes over znin 2 s 4 yuanyuan li, jingyu cai, mingming hao, zhaohui li research institute of photocatalysis, state key laboratory of photocatalysis on energy and environment, college of chemistry, fuzhou university, fuzhou 350116, p.
This method was once an important industrial process for the manufacture of acetylene. The resulting vinyl sulfides underwent nicatalyzed kumada cross coupling with grignard reagents. The conversion is highly markovnikov selective and is capable of utilizing aromatic, benzylic, and aliphatic thiols. Under the optimized conditions, rhodiumcatalyzed hydrothiolation of terminal alkynes proceeds regio and stereoselectively to afford the corresponding vinyl sulfides via an antimarkovnikov and synaddition process. Highly stereoselective antimarkovnikov hydrothiolation of alkynes and electrondeficient alkenes by a supported cunhc complex. Highly regio and stereocontrolled synthesis of vinyl. Apr 30, 2014 in sharp contrast to many examples of transitionmetalcatalyzed hydrothiolation of alkynes, the corresponding catalytic addition of thiols to alkenes has remained undeveloped. Pdf onwater hydrothiolation reaction between terminal alkyne and thiol has been probed in the presence of various additives.
Herein, we describe a simple and inexpensive protocol for the hydrothiolation of alkynes. Organoactinidemediated hydrothiolation of terminal alkynes with. Aromatic alkynes yield corresponding 1alkenyl sulfides, whereas aliphatic. Stereoselective hydrothiolation of alkynes catalyzed by cesium base. Markovnikov addition of thiols to unactivated alkenes and alkynes was demonstrated by using 3,4. Nickelcatalysed selective migratory hydrothiolation of alkenes and alkynes with thiols. Rhodiumcatalyzed alkyne hydrothiolation with aromatic and. In this manuscript, flowerlike microspheres of znin2s4 consisting of interweaving nanoflakes were prepared by a solvothe. Reaction in which the elements of water h and oh are. Reaction in which halogen is introduced into a molecule 3 hydration.
Onepot hydrothiolationkumada coupling protocol has been developed. Additions are the most common reactions using alkenes and alkynes addition to. Regio and stereoselective synthesis of vinyl sulfides via phsebrcatalyzed hydrothiolation of alkynes. Coppercatalyzed selective hydroamination reactions of alkynes. Palladium and copper cocatalyzed markovnikov hydrothiolation. Markovnikov adducts in excellent yields within only a few minutes at 120 c in the presence of only 0.
Different energy and geometry changes may be required for additions to an alkyne and an alkene so some surprising outcomes may occur with alkynes. In this manuscript, flowerlike microspheres of znin 2 s 4 consisting of interweaving nanoflakes were prepared by a solvothermal method and were applied for the first time in the visible light initiated hydrothiolation of alkenes and alkynes. Jun, 2018 we learned about hydrogenation when we first checked out addition reactions, but we were doing that with alkenes. Pdf highly stereoselective antimarkovnikov hydrothiolation.
Alkynes can have multiple reaction partners, such as other alkynes, alkenes, allenes, and c arbonylimine systems for the cycloisomerization leading to a variety of different carbocycles and heterocycles. Lewisacidic caoso 2 c 4 f 9 2 caonf 2 was synthesized for the first time and was shown to be an excellent catalyst for the transformation. Methods of preparation of alkynes by dehydrohalogenation of. Radical and nucleophilic thiol addition across alkynes in an antimarkovni kov fashion is wellknown. The reaction is highly selective and has a wide substrate scope.
Twostep reaction in which an alkene is converted to an alkene with a hydroxyl substituent which may tauromerize to a carbonyl. Stereoselective hydrothiolation of alkynes catalyzed by cesium. Bishydrothiolation of alkynes providing antimarkovnikov dithioacetals is reported. For example, bhadra and ranu 54, in their studies on waterpromoted.
17 1264 843 408 1548 895 960 357 893 540 12 1035 933 738 1134 1052 295 297 405 848 709 1084 164 303 452 1402 122 1457 47 1258 1555 1133 230 158 1288 1 592 215 109 1090 403 1328 1092 530 932 1404