Richard F. Heck
Heck in 2010
Richard Frederick Heck
August 15, 1931
|Died||October 10, 2015 84) (aged|
|Residence||Quezon City, Philippines|
|Alma mater||University of California, Los Angeles|
|Known for||Heck reaction|
|Spouse(s)||Socorro Nardo-Heck (died 2012)|
|Awards||Nobel Prize in Chemistry (2010)|
|Institutions|| University of Delaware |
De La Salle University
|Doctoral advisor||Saul Winstein|
Richard Frederick Heck (August 15, 1931 – October 10, 2015) was an American chemist noted for the discovery and development of the Heck reaction, which uses palladium to catalyze organic chemical reactions that couple aryl halides with alkenes. The analgesic naproxen is an example of a compound that is prepared industrially using the Heck reaction.
The Heck reaction is the chemical reaction of an unsaturated halide with an alkene in the presence of a base and a palladium catalyst to form a substituted alkene. It is named after Tsutomu Mizoroki and Richard F. Heck. Heck was awarded the 2010 Nobel Prize in Chemistry, which he shared with Ei-ichi Negishi and Akira Suzuki, for the discovery and development of this reaction. This reaction was the first example of a carbon-carbon bond-forming reaction that followed a Pd(0)/Pd(II) catalytic cycle, the same catalytic cycle that is seen in other Pd(0)-catalyzed cross-coupling reactions. The Heck reaction as a way to substitute alkenes.
Palladium is a chemical element with symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them.
A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei, and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.
For his work in palladium-catalyzed coupling reactions and organic synthesis, Heck was awarded the 2010 Nobel Prize in Chemistry, shared with the Japanese chemists Ei-ichi Negishi and Akira Suzuki.
Palladium-catalyzed coupling reactions comprise a family of cross-coupling reactions that employ palladium complexes as catalysts. It is an active area of research and applications in homogeneous catalysis. In 2010, the Nobel Prize in Chemistry was awarded to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki for their work on palladium-catalyzed cross couplings in organic synthesis.
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one of the most important branches of organic chemistry. There are several main areas of research within the general area of organic synthesis: total synthesis, semisynthesis, and methodology.
The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature, peace, and physiology or medicine. This award is administered by the Nobel Foundation, and awarded by Royal Swedish Academy of Sciences on proposal of the Nobel Committee for Chemistry which consists of five members elected by Academy. The award is presented in Stockholm at an annual ceremony on December 10, the anniversary of Nobel's death.
Heck was born in Springfield, Massachusetts in 1931.He earned his Ph.D. in physical organic chemistry in 1954 at the University of California, Los Angeles (UCLA), working under the supervision of Dr. Saul Winstein. After two periods of postdoctoral research at the ETH in Zurich, Switzerland, and then back at UCLA, Heck took a position with the Hercules Corporation in Wilmington, Delaware in 1957. After productive research work at Hercules, he was hired by the University of Delaware's Department of Chemistry and Biochemistry in 1971. Heck was a professor of chemistry at the University of Delaware. In 2012, he was appointed by De La Salle University in Manila as adjunct professor in its chemistry department.
Springfield is a city in the state of Massachusetts, United States, and the seat of Hampden County. Springfield sits on the eastern bank of the Connecticut River near its confluence with three rivers: the western Westfield River, the eastern Chicopee River, and the eastern Mill River. As of the 2010 Census, the city's population was 153,060. As of 2017, the estimated population was 154,758, making it the 4th-most populous city in New England, and the 12th-most populous in the Northeastern United States. Metropolitan Springfield, as one of two metropolitan areas in Massachusetts, had a population of 692,942 as of 2010.
The University of California, Los Angeles (UCLA) is a public research university in Los Angeles. It became the Southern Branch of the University of California in 1919, making it the second-oldest undergraduate campus of the 10-campus University of California system. It offers 337 undergraduate and graduate degree programs in a wide range of disciplines. UCLA enrolls about 31,000 undergraduate and 13,000 graduate students and had 119,000 applicants for Fall 2016, including transfer applicants, the most applicants for any American university.
Saul Winstein was a Canadian chemist who discovered the Winstein reaction. He argued a non-classical cation was needed to explain the stability of the norbornyl cation. This fueled a debate with Herbert C. Brown over the existence of σ-delocalized carbocations. Winstein also first proposed the concept of an intimate ion pair. He was co-author of the Grunwald-Winstein equation, concerning solvolysis rates.
The development of the Heck reaction began with Heck's investigations of the coupling of arylmercury compounds with olefins using palladium as a catalyst during the late 1960s.This work was published in a series of seven consecutive articles in the Journal of the American Chemical Society (JACS) for which Heck was the sole author.
Organomercury refers to the group of organometallic compounds that contain mercury. Typically the Hg–C bond is stable toward air and moisture but sensitive to light. Important organomercury compounds are the methylmercury(II) cation, CH3Hg+; ethylmercury(II) cation, C2H5Hg+; dimethylmercury, (CH3)2Hg, diethylmercury, and merbromin ("Mercurochrome"). Thiomersal is used as a preservative for vaccines and intravenous drugs.
The Journal of the American Chemical Society is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society. The journal has absorbed two other publications in its history, the Journal of Analytical and Applied Chemistry and the American Chemical Journal. It publishes original research papers in all fields of chemistry. Since 2002, the journal is edited by Peter J. Stang. In 2014, the journal moved to a hybrid open access publishing model.
During the early 1970s, Mizoroki independently reported the use of the less toxic aryl halides as the coupling partner in the reaction.During his career, Heck continued to improve the transformation, developing it into a powerful synthetic method for organic synthesis.
The importance of this reaction grew slowly in the organic synthesis community. In 1982, Heck was able to write an Organic Reactions chapter that covered all the known instances in just 45 pages.By 2002, applications had grown to the extent that the Organic Reactions chapter published that year, limited to intramolecular Heck reactions, covered 377 pages. These reactions, a small part of the total, couple two parts of the same molecule. Today, the Heck reaction stands as one of the widely used methods for the creation of carbon-carbon bonds in the synthesis of organic chemicals. This reaction has been subject to numerous scientific review articles, including a ~600 page monograph dedicated to this subject published in 2009.
Intramolecular in chemistry describes a process or characteristic limited within the structure of a single molecule, a property or phenomenon limited to the extent of a single molecule.
In chemistry, an organic compound is generally any chemical compound that contains carbon. Due to carbon's ability to catenate, millions of organic compounds are known. Study of the properties and synthesis of organic compounds is the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds, along with a handful of other exceptions, are not classified as organic compounds and are considered inorganic. No consensus exists among chemists on precisely which carbon-containing compounds are excluded, making the definition of an organic compound elusive. Although organic compounds make up only a small percentage of the Earth's crust, they are of central importance because all known life is based on organic compounds. Most synthetically produced organic compounds are ultimately derived from petrochemicals consisting mainly of hydrocarbons.
Heck's work set the stage for a variety of other palladium-catalyzed coupling reactions, including those of aryl halides with derivatives of boronic acid (Suzuki–Miyaura coupling), organotin reagents (Stille coupling), organomagnesium compounds (Kumada-Corriu coupling), silanes (Hiyama coupling), and organozincs (Negishi coupling), as well as with amines (Buchwald–Hartwig amination) and alcohols.These palladium-catalyzed coupling reactions are now widely practiced in organic synthesis, including in the chemical engineering production of certain organic compounds in factories.
Of the several reactions developed by Heck, the greatest societal impact has been from the palladium-catalyzed coupling of an alkyne with an aryl halide. This is the reaction that was used to couple fluorescent dyes to DNA bases, allowing the automation of DNA sequencing and the examination of the human genome. In Sonogashira's original report of what is now known as the Sonogashira coupling, his group modified an alkyne coupling procedure previously reported by Heck, by adding a copper(I) salt.
Heck's contributions are not limited to the activation of halides by the oxidative addition of palladium. Heck was the first to fully characterize a π-allyl metal complex,and the first to elucidate the mechanism of alkene hydroformylation.
Heck retired from the University of Delaware in 1989, where he became the Willis F. Harrington Professor Emeritus in the Department of Chemistry and Biochemistry. Its annual lectureship was named in his honor in 2004. In 2005, he was awarded the Wallace H. Carothers Award, which recognizes creative applications of chemistry that have had substantial commercial impact. He was awarded the 2006 Herbert C. Brown Award for Creative Research in Synthetic Methods.On 6 October 2010, the Swedish Royal Academy of Sciences awarded Heck the Nobel Prize in Chemistry. He shared the 2010 Nobel Prize with Ei-ichi Negishi and Akira Suzuki "for palladium-catalyzed cross couplings in organic synthesis." In 2011, Heck was awarded the Glenn T. Seaborg Medal for his work on palladium-catalyzed cross couplings.
Heck moved to the Philippines after retirementin 1989 with his wife, Socorro Nardo-Heck. The couple had no children.
Heck died on October 9, 2015 in Manila in a public hospital.His wife predeceased him by 2 years.
Heck received honorary doctorates from Uppsala University (Pharmacy)and De La Salle University (Science).
The Stille reaction, or the Migita–Kosugi–Stille coupling, is a chemical reaction widely used in organic synthesis which involves the coupling of an organotin compound with a variety of organic electrophiles via palladium-catalyzed coupling reaction.
The Suzuki reaction is an organic reaction, classified as a coupling reaction, where the coupling partners are a boronic acid and an organohalide catalyzed by a palladium(0) complex. It was first published in 1979 by Akira Suzuki and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their effort for discovery and development of palladium-catalyzed cross couplings in organic synthesis. In many publications this reaction also goes by the name Suzuki–Miyaura reaction and is also referred to as the Suzuki coupling. It is widely used to synthesize poly-olefins, styrenes, and substituted biphenyls. Several reviews have been published describing advancements and the development of the Suzuki Reaction. The general scheme for the Suzuki reaction is shown below where a carbon-carbon single bond is formed by coupling an organoboron species (R1-BY2) with a halide (R2-X) using a palladium catalyst and a base.
The Sonogashira reaction is a cross-coupling reaction used in organic synthesis to form carbon–carbon bonds. It employs a palladium catalyst as well as copper co-catalyst to form a carbon–carbon bond between a terminal alkyne and an aryl or vinyl halide.
A coupling reaction in organic chemistry is a general term for a variety of reactions where two fragments are joined together with the aid of a metal catalyst. In one important reaction type, a main group organometallic compound of the type R-M reacts with an organic halide of the type R'-X with formation of a new carbon-carbon bond in the product R-R'
Organopalladium chemistry is a branch of organometallic chemistry that deals with organic palladium compounds and their reactions. Palladium is often used as a catalyst in the reduction of alkenes and alkynes with hydrogen. This process involves the formation of a palladium-carbon covalent bond. Palladium is also prominent in carbon-carbon coupling reactions, as demonstrated in tandem reactions.
The Hiyama coupling is a palladium-catalyzed cross-coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon–carbon bonds. This reaction was discovered in 1988 by Tamejiro Hiyama and Yasuo Hatanaka as a method to form carbon-carbon bonds synthetically with chemo- and regioselectivity. The Hiyama coupling has been applied to the synthesis of various natural products.
The Negishi coupling is a widely employed transition metal catalyzed cross-coupling reaction. The reaction couples organic halides or triflates with organozinc compounds, forming carbon-carbon bonds (c-c) in the process. A palladium (0) species is generally utilized as the metal catalyst, though nickel is sometimes used:
Transmetalation (alt. spelling: transmetallation) is a type of organometallic reaction that involves the transfer of ligands from one metal to another. It has the general form:
The Buchwald–Hartwig amination is a chemical reaction used in organic chemistry for the synthesis of carbon–nitrogen bonds via the Palladium-catalyzed coupling reactions of amines with aryl halides. Although Pd-catalyzed C-N couplings were reported as early as 1983, Stephen L. Buchwald and John F. Hartwig have been credited, whose publications between 1994 and the late 2000s established the scope of the transformation. The reaction's synthetic utility stems primarily from the shortcomings of typical methods for the synthesis of aromatic C–N bonds, with most methods suffering from limited substrate scope and functional group tolerance. The development of the Buchwald–Hartwig reaction allowed for the facile synthesis of aryl amines, replacing to an extent harsher methods while significantly expanding the repertoire of possible C–N bond formation.
The Castro–Stephens coupling is a cross coupling reaction between a copper(I) acetylide and an aryl halide in pyridine, forming a disubstituted alkyne and a copper(I) halide.
In organic chemistry, the Kumada coupling is a type of cross coupling reaction, useful for generating carbon–carbon bonds by the reaction of a Grignard reagent and an organic halide. The procedure uses transition metal catalysts, typically nickel or palladium, to couple a combination of two alkyl, aryl or vinyl groups. The groups of Robert Corriu and Makoto Kumada reported the reaction independently in 1972.
XPhos is a phosphine ligand derived from biphenyl. Its palladium complexes exhibit high activity for Buchwald-Hartwig amination reactions involving aryl chlorides and aryl tosylates. Both palladium and copper complexes of the compound exhibit high activity for the coupling of aryl halides and aryl tosylates with various amides. It is also an efficient ligand for several commonly used C–C bond-forming cross-coupling reactions, including the Negishi, Suzuki, and the copper-free Sonogashira coupling reactions. It is especially efficient and general when employed as a (2-aminobiphenyl)-cyclometalated palladium mesylate precatalyst complex, XPhos-G3-Pd, which is commercially available and stable to bench storage. The ligand itself also has convenient handling characteristics as a crystalline, air-stable solid.
The Heck-Matsuda (HM) reaction is an organic reaction and a type of palladium catalysed arylation of olefins that uses arenediazonium salts as an alternative to aryl halides and triflates.
Decarboxylative cross coupling reactions are chemical reactions in which a carboxylic acid is reacted with an organic halide to form a new carbon-carbon bond, concomitant with loss of CO2. Aryl and alkyl halides participate. Metal catalyst, base, and oxidant are required.
The Catellani reaction was discovered by Marta Catellani and co-workers in 1997. The reaction uses aryl iodides to perform bi- or tri-functionalization, including C-H functionalization of the unsubstituted ortho position(s), followed a terminating cross-coupling reaction at the ipso position. This cross-coupling cascade reaction depends on the ortho-directing transient mediator, norbornene.
In organometallic chemistry, palladium-NHC complexes are a family of organopalladium compounds in which palladium forms a coordination complex with N-Heterocyclic carbenes (NHCs). They have been investigated for applications in homogeneous catalysis, particularly cross-coupling reactions.
Tamejiro Hiyama is a Japanese organic chemist. He is best known for his work in developing the Nozaki-Hiyama-Kishi reaction and the Hiyama coupling. He is currently a professor at the Chuo University Research and Development Initiative, and a Professor Emeritus of Kyoto University.
In organic and organometallic chemistry, dialkylbiaryl phosphine (or dialkylbiarylphosphine) ligands are phosphorus-containing supporting ligands that are used to modulate the chemical reactivity of palladium and other transition metal based catalysts. They were first described by Stephen L. Buchwald in 1998 for applications in palladium-catalyzed coupling reactions to form carbon-nitrogen and carbon-carbon bonds. Before their development, use of first- or second-generation phosphine ligands for palladium-catalyzed C-N bond-forming cross-coupling (e.g., tris(o-tolyl)phosphine and BINAP, respectively) necessitated harsh conditions, and the scope of the transformation was severely limited. The Suzuki-Miyaura and Negishi cross-coupling reactions were typically performed with Pd(PPh3)4 as catalyst and were mostly limited to aryl bromides and iodides at elevated temperatures, while the widely available aryl chlorides were unreactive. The development of new classes of ligands was needed to address these limitations.
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