Imidazolium saltstabilized palladium nanoparticles. Hydrosilylation of alkynes catalyzed by ruthenium carbene. This reaction represents a notable and efficient example on coppercatalyzed hydrosilylatioin of alkynes, which shows excellent recognition between the terminal and internal triple bonds. This protocol used relatively simple and available starting materials to construct more valuable products with excellent chemo. The catalytic hydrosilylation reaction of terminal alkynes with hydrosilanes proceeds in high yields as well as with eselectivity by using a cobaltdiphosphine complex. Pdf fifty years of hydrosilylation in polymer science. A coppercatalyzed antimarkovnikov hydrosilylation of alkynes with phsih3 was reported. Various heteroaromatic and aliphatic substituted terminal alkynes underwent this reaction to afford the e. Rhodium complexes ligated by imidazoliumsubstituted phosphine were used as catalysts in the hydrosilylation of alkynes 1heptyne. Methods for hydrosilylation of terminal alkynes were developed some time ago, particularly for the preparation of cis and trans.
The simula catalyzed hydrosilylation of alkynes tions identified the ratedetermining step and provided a theo retical activation energy 8. The final outcome of the reaction depends on the catalyst, the alkyne, and the silane employed. Aug 11, 2020 for terminal alkynes the addition of water follows the markovnikov rule, as in the second example below, and the final product ia a methyl ketone except for acetylene, shown in the first example. Hydrosilylation of alkynes catalysed by platinum on titania core. Recent advances in the hydrosilylation of alkynes scientific. The international union of pure and applied chemistry iupac names for alkynes parallel those of alkenes, except that the family ending is yne rather than ene. Photoactivated hydrosilylation reaction of alkynes. Schiff base cobaltii complexcatalyzed highly markovnikov. Cobaltcatalyzed asymmetric synthesis of gembissilyl. Rhodiumcatalyzed reaction of alkynes with hydrosilanes. Functionalization of porous silicon with alkenes and alkynes. A general mechanistic overview of hydrosilylation is provided along with.
Ironcatalyzed regiodivergent alkyne hydrosilylation american. Highly regioselective hydrosilylation of unsymmetric. Selective hydrosilylation of 1alkynes using iridium catalyst. Alkynes using iridium catalyst with biphosphinine ligand. Functionalization of porous silicon with alkenes and.
Hydrosilylation of internal alkynes catalyzed by tris. Additionally, intramolecular variants have raised new questions regarding the mechanism of trans hydrosilylation of alkynes. Regioand stereoselective hydrosilylation of alkynes catalyzed by. The cyclopentadienylruthenium complex developed by trost et al. Pdf regio and enantioselective cobaltcatalyzed sequential. The silylimination of alkynes with hydrosilanes and noctyl isocyanide, and the subsequent 1,4 hydrosilylation of the resulting.
The design and development of highly efficient and selective methods for the synthesis of alkenylsilanes, based on alkyne hydrosilylation, have been the subjects of extensive study, because of. Jan 03, 2005 hydrosilylation of terminal alkynes with a variety of silanes catalyzed by cl 2 pcy 3 2 ru chph 1 affords mainly the zisomer via trans addition in excellent yields. Regiocontrol in the cobaltcatalyzed hydrosilylation of. As expected, hydrosilylation of 2 with triethoxysilane 1. For example, alkynes undergo many of the typical addition reactions of alkenes. It has since been found that hydrosilylation of a variety of alkenes and alkynes upon porous silicon is achieved in the presence of carbocation salts figure 1 6.
Friendly platinum catalysts for the highly stereoselective hydrosilylation of alkynes and alkenes dr. Hydrosilylation of alkynes mediated by the lewis acid etalcl2 was initially communicated, utilizing soluble, molecular trisubstituted silanes such as triethylsilane, ch3ch23sih. The iridiumcatalyzed hydrosilylation of alkynes in the presence of 4,4. For internal alkynes the triplebond is within a longer chain the addition of water is not regioselective. Protein modification via alkyne hydrosilylation using a. Functional groups covalently bound to the surface of porous silicon through etalcl2 mediated hydrosilylation of alkynes and alkenes. Coiadpph3ch2tms 1 iad 1,3diadamantylimidazol2ylidene facilitates regio and stereoselective hydrosilylation of terminal, symmetrical internal, and trimethylsilylsubstituted unsymmetrical internal alkynes to produce. Polymers free fulltext fifty years of hydrosilylation. Hydrosilylation of cc bonds as a most versatile synthetic route to formation of sic bond initiated by freeradicals has been wellknown for 60 years, while that catalysed by platinum starting from speier catalyst and other tm complexes for 50 years. The distribution of the products is found to vary consider. Vinylsilanes are very useful intermediates in organic synthesis, especially for palladiumcatalyzed crosscoupling reactions.
Hydrosilylation, also called catalytic hydrosilation, describes the addition of sih bonds across unsaturated bonds. The method can be applied to the hydrosilylation of 1,4enynes containing an internal alkyne to give the corresponding alkenes with excellent eselectivity. Efficient and selective hydrosilylation of alkenes and alkynes. Highly regioselective silylcupration of terminal alkynes reported by loh is.
Complex 1 proved an efficient catalyst for hydrosilylation of alkynes. The numeric values correspond to the i cdc of the surfacebound vinyl group as measured by transmission ftir. The reaction of arylsubstituted alkynes proceeded when an excess molar amount of hydrosilane relative to the isocyanide was added. A threecoordinate cobalti complex exhibits high catalytic efficiency and selectivity as well as good functional group compatibility in alkyne hydrosilylation. Experimental and computational studies of the ruthenium. Theoretical study on coppercatalyzed reaction of hydrosilane. In situ ftir measurements were performed on a mettlertoledo reactir 15 spectrometer equipped. These complexes were then tested in the model hydrosilylation reaction and compared with the karstedt catalyst.
Lewis acid mediated hydrosilylation on porous silicon surfaces. Hydrosilylation reactions, the commonly antimarkovnikov additions of silanes to unsaturated bonds present in compounds such as alkenes and alkynes, offer numerous unique and advantageous properties for the preparation of polymeric materials, such as high yields and stereoselectivity. Documented herein are the benefits of a versatile regiodivergent and stereoselective hydrosilylation of alkynes in the presence of only 0. Lewis acid mediated functionalization of porous silicon. In terminal alkynes, cis addition of hydrosilane gives the eproduct while trans addition gives the zproduct. Hydride abstraction initiated hydrosilylation of terminal. Hydrosilylation of alkenes and their derivatives springerlink. The hydrosilylation of alkynes in the presence of tmbp proceeds effectively to give. The ruthenium hydride complex pcy32coruhcl was found to be a highly effective catalyst for the regio and stereoselective hydrosilylation of alkynes to form vinylsilane products. Methods for hydrosilylation of terminal alkynes were developed some time ago, particularly for the preparation of. A variety of hydrosilanes react with both terminal and internal alkynes to furnish the corresponding vinyl silanes in. Pdf an effective hydrosilylation of alkynes in supercritical co 2. The design and development of highly efficient and selective methods for the synthesis of alkenylsilanes, based on alkyne hydrosilylation, have been the subjects of extensive study, because of their versatile application in organic synthesis and material science.
Rhodiumcatalyzed reaction of alkynes with hydrosilanes and n. Eselective hydrosilylation of terminal alkynes by cobalt. A number of transition metal catalysts have been devised to execute these reactions in a regio and stereocontrolled fashion figure 1. In general, hydrosilylation of terminal alkynes produces the three different isomers, cis, trans and geminal, as a result of both 1,2 syn and anti and 2,1 additions, respectively. The reaction of arylsubstituted alkynes proceeded when an excess molar amount of. A variety of functionalized aromatic and aliphatic alkynes undergo this transformation, yielding z. Supporting materials a highly selective synthesis of new. In situ ftir measurements were performed on a mettlertoledo reactir 15 spectrometer equipped with 9. Evinylsilanes highly selectively in moderate to high yields, whereas a similar hydrosilylation in the absence of tmbp produces.
The combustion of acetylene releases more energy per mole of product formed than any other hydrocarbons. View the article pdf and any associated supplements and figures for a period of 48 hours. Alkynes are similar to alkenes in both physical and chemical properties. Hydrosilylation of terminal alkynes with catalyst 1a. Internal alkynes as illustrated in scheme 1, nonselective hydrosilylation of internal alkynes would potentially give four isomeric addition products. Sep 02, 2019 the selectivity of alkyne hydrosilylation processes is known to depend on several factors, such as the metal catalysts and ligands, steric or electronic properties of hydrosilanes and alkynes, etc. Hydrosilylation of alkynes catalysed by platinum on titania. Ch is a colorless gas that burns in oxygen to form co 2 and h 2o. Hydrosilylation of terminal alkynes catalyzed by a ono. Inspired by the development of a cationic ruthenium catalyst cprumecn 3pf 6 1 by trost and ball,36,37 we examined the catalysts ability to catalyze hydrosilylation under biocompatible, aqueous conditions. A variety of hydrosilanes react with both terminal and internal alkynes to furnish the corresponding vinyl silanes in high yields and short reaction times as well as in a regio and stereoselective manner.
Alkyne 2 eq 1 represents a reasonable test with a common functionality which cannot survive many of the reduction methods if the alkyne reduces well. Zvinylsilane products were selectively formed for sterically nondemanding terminal alkynes, while evinylsilane products resulted from sterically demanding terminal alkynes. Among the different catalysts, platinum catalysts are usually. Yi zhaoa,c, yuxia liub, siwei bib, yongjun liua, anorthwest institute of plateau biology, chinese academy of sciences, xining, qinghai 81, china b school of chemistry and chemical engineering, qufu normal university, qufu 273165, pr china. Hydrosilylation of aliphatic terminal alkynes a cobaltcatalyzed sequential highly enantioselective double hydrosilylation of aliphatic alkynes for the precise synthesis of chiralgembissilylalkanes was achieved. Pincer cobalt complexcatalyzed zselective hydrosilylation. Selective hydrosilylation of 1alkynes using iridium. Hydrosilylation of alkynes catalyzed by platinum on carbon. Theoretical study on coppercatalyzed reaction of hydrosilane, alkyne and carbon dioxide. Highly efficient and reusable alkyne hydrosilylation. Hydrosilylation of terminal alkynes catalyzed by a onopincer. Highly regioselective hydrosilylation of unsymmetric alkynes. Visible light accelerated hydrosilylation of alkynes using platinum.
Rutheniumcatalyzed hydrosilylation of alkynes by using. An example of specific selectivity is in platinum catalized hydrosilylation. Platinumdiaminocarbene complexes work as transitionmetal photocatalysts for the hydrosilylation of alkynes. The difficulty of regiocontrol in hydrosilylation, however, has prevented its application to unsymmetric alkyne system for obtaining a mixture of regioisomers. Pdf hydrosilylation of a wide group of alkynes terminal and internal with four structurally different silanes has been for the first time. The trost group has demonstrated that hydrosilylation of internal alkynes with cprumecn 3pf 6 gives trisubstituted zvinylsilanes exclusively, as a result of trans addition of the. The most thermodynamically stable and usually major reaction product is the. These reactions require to be catalyzed, for which platinum compounds were used in the initial stages. The hydrosilylation of alkynes offers a greater synthetic challenge than alkenes because of the higher reactivity of the triple bond and the potential for a broader. Iridiumcatalyzed markovnikov hydrosilylation of terminal.
Ordinarily the reaction is conducted catalytically and usually the substrates are unsaturated organic compounds. Gupta,a stephen wallace,bc yuteng wu,a fengzhi zhang,a hannah f. Alkynes are hydrocarbons with carbontocarbon triple bonds and properties much like those of alkenes. This chapter describes recent progress in the development of new alkyne hydrosilylation protocols as well as related processes employing hydrosilanes and alkyne derivatives leading to acyclic and cyclic alkenylsilanes, taking into. Jan, 2021 range of alkynes in hydrosilylation with diphenylsilane. This study aims to answer the general question of how to control hydrosilylation regioselectivity with unsymmetric alkynyl groups. Of the available methods for preparation of vinylsilanes, the hydrosilylation of alkynes is the most direct and atomeconomical approach scheme 1. Thermal and uv hydrosilylation of alcoholbased bifunctional. Hydrosilylation of terminal alkynes in the presence of platinum complexes pro vides usually exclusive cisaddition to produce the.
Regiocontrol in the cobaltcatalyzed hydrosilylation of alkynes. This chapter describes recent progress in the development of new alkyne hydrosilylation protocols as well as related processes employing hydrosilanes and alkyne. The stereoselectivity of these reactions suggests the importance of the electronwithdrawing. Hydrosilylation has been called the most important application of platinum in homogeneous catalysis. Photoactivated hydrosilylation reaction of alkynes request pdf. Regio and stereoselective hydrosilylation of alkynes. Polymers free fulltext fifty years of hydrosilylation in. Transitionmetal catalyzed hydrosilylation of terminal alkynes is the most straightforward and atomeconomical methodology for the preparation of.
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