Recent advances in alkylidene carbene chemistry

Grainger, Richard S.; Munro, Kevin R.

doi:10.1016/j.tet.2015.06.053

Cited by 48 publications

(58 citation statements)

References 250 publications

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“…20) This reaction was successfully applied to α,β-unsaturated carbonyl compounds under neutral conditions to obtain the desired nitriles. Cholest-4-en-3-one (27) and α-ionone (29) gave the corresponding nitriles 28 and 30 (entries 9 and 10, Table 4), whereas under general tosylmethyl isocyanide (TosMIC) 22) conditions in the presence of t-BuOK in DMF, nitriles 28 and 30 were detected only by TLC in trace amounts. 20) The CPs-SmI 2 method was employed in a variety of organic syntheses, 1) for instance, in the synthesis of the natural spongian pentacyclic diterpene, aplyroseol-1 and its related compounds; in the synthesis of hydroxyethene isosteres of human immunodeficiency virus (HIV) protease-catalyzed phenylalanine (Phe)-proline (Pro) hydrolysis transition state; in the transformation of aldol product from Boc-L-phenylalaninal into lactone; in the synthesis of sweroside aglycon; and in the preparation of nitriles from chiral ketone in the total synthesis of (±)-aphidicolin.…”

Section: Reductive Cyanation Of Ketones and Aldehydesmentioning

confidence: 99%

“…25) In continuation of our recent program on the use of CPs, we were encouraged to look once again at allylic rearrangements of CPs for a practicable synthetic method for key intermediate 41 for 3-(tetrazol-5-yl)-3,5-pregnadien-20-one (TzPD, 43), a potent 5α-reductase inhibitor (IC 50 : 15.6 nM), from pregnene-3,20-dione (39) in 92% overall yield in four steps, as shown in Chart 11 26) Furthermore, it should be noted that the C 20 -CP of bis-CP 40 also plays a significant role as a protecting group for the C 20 -ketone. 27) 3.1. Overview of Alkylidene Carbene-Generation Alkylidene carbenes (44) can be used in many synthetically valuable reactions including [1,2]-migration, ylide formation, alkyne cyclopropanation and [1,5]-C-H bond insertion.…”

Section: Allylic Rearrangement Of Cpsmentioning

confidence: 99%

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Development of New Synthetic Reactions Using Hetero-Heavy Atoms and Their Application to Synthesis of Biofunctional Molecules

Harusawa

2020

CHEMICAL & PHARMACEUTICAL BULLETIN

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Novel reactions using hetero-heavy atoms (P, S, Si, Se, and Sn) were developed and applied to the synthesis of biofunctional molecules and some medicine-candidates, in which the following items are covered. 1) Development of introduction of C 1-unit using cyanophosphates (CPs). 2) Carbene-generation under neutral condition from CPs and its application to organic synthesis. 3) [3,3]Sigmatropic rearrangement-ring expansion reactions of medium-sized cyclic thionocarbonates containing a sulfur atom and their application to natural product synthesis. 4) Stereoselective synthesis of novel β-imidazole C-nucleosides via diazafulvene intermediates and their application to investigating ribozyme reaction mechanism. 5) Developments of novel histamine H 3-and H 4-receptor ligands using new synthetic methods involving Se or Sn atoms.

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Section: Reductive Cyanation Of Ketones and Aldehydesmentioning

confidence: 99%

Section: Allylic Rearrangement Of Cpsmentioning

confidence: 99%

Development of New Synthetic Reactions Using Hetero-Heavy Atoms and Their Application to Synthesis of Biofunctional Molecules

Harusawa

2020

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…The nitrogen accompany the others components of the atmosphere even today. As syntone methylene is the most important compound in formation of various organic compounds (Zugravescu et al 1970(Zugravescu et al , 1971Kirmse 1971;Surpateanu et al 1976;Becerra & Monty Frey 1987;Surpateanu & Lungu 2011;Grainger & Munro 2015). Some methylation of proteic chains shows an epigenetic role (Wegner et al 2014;Guan et al 2015;Nickel & Stadler 2015).…”

Section: Proteinogenic Amino Acidsmentioning

confidence: 99%

“…1970, 1971; Kirmse 1971; Surpateanu et al . 1976; Becerra & Monty Frey 1987; Surpateanu & Lungu 2011; Grainger & Munro 2015). Some methylation of proteic chains shows an epigenetic role (Wegner et al .…”

Section: Proteinogenic Amino Acidsmentioning

confidence: 99%

Syntone chemistry and prebiotic stage in life evolution 1. Aziridinone, a key compound in formation of the first proteinogenic amino acids and polypeptides

Surpateanu

2017

International Journal of Astrobiology

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In this paper is proposed a new theory concerning the formation of the first proteinogenic amino acids and their corresponding polypeptides starting of three syntones: methylene, nitrene and carbon monoxide. First, at low temperature in nitrogen, these three syntones form aziridinone, an asimetric compound in special conditions. Next, by a series of radical chain, izomerization, cyclization, elimination and polymerization reactions, apparently without a well defined transition states are formed a series of precursor syntones. Finally, these more structured syntones at the contract with the components of primary atmosphere, especially with water, ammonia, hydrogen sulphide, even with carbon dioxide and methane offer the first proteinogenic amino acids and their first corresponding polypeptides. As a very important aspect, the aziridinone cycle furnish the backbone of proteinogenic amino acids. The formation of each proteinogenic amino acid moiety also as its participation to construction of polypeptide structures were estimated by two parameters: (1) the complex structural factor, Fe and (2) the participation coefficient, Cp respectively. Dominantly, the quantitative results given in this paper were acquired by structural, thermodynamical and reactivity studies using DGauss with the B88-LYP GGA energy functional with high integral accuracy. Finally, an experimental assembly for obtention of amino acids and polypeptides is proposed. Brief, the three initial syntones: CH2, NH and CO, in nitrogen form aziridinone. That, in reactions with the same three syntones form, the more structured syntone precursors of proteinogenic amino acids and polypeptides. At the contact with primary atmosphere components are formed the first proteinogenic amino acids and polypeptides. The first polypeptides appear from polypeptide precursors and not from proteinogenic amino acids.

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“…Alkylidenecarbenes ( 1 ), and surrogate carbenoids ( 2 ), often undergo 1,2-shifts to furnish alkynes ( 3 ) by a process commonly referred to as the Fritsch-Buttenberg-Wiechell (FBW) rearrangement (Scheme 1a) [1,2,3,4,5,6]. By extending this method to cyclic alkylidenecarbenes ( 4 ) and carbenoids ( 5 ), in which the formally sp 2 -hybridized carbon connected to the carbene center is part of a ring, strained cycloalkynes ( 6 ) have also been generated (Scheme 1b) [4,7,8,9].…”

Section: Introductionmentioning

confidence: 99%

Ring Expansion of Alkylidenecarbenes Derived from Lactams, Lactones, and Thiolactones into Strained Heterocyclic Alkynes: A Theoretical Study

Just

Pankauski

et al. 2019

Molecules

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Strained cycloalkynes are of considerable interest to theoreticians and experimentalists, and possess much synthetic value as well. Herein, a series of cyclic alkylidenecarbenes—formally obtained by replacing the carbonyl oxygen of four-, five-, and six-membered lactams, lactones, and thiolactones with a divalent carbon—were modeled at the CCSD(T)/cc-pVTZ//B3LYP/6-311+G** and CCSD(T)/cc-pVTZ//CCSD/6-311+G** levels of theory. The singlet carbenes were found to be more stable than the triplets. The strained heterocyclic alkynes formed by ring expansion of these singlet carbenes were also modeled. Interestingly, the C≡C bonds in the five-membered heterocycles, obtained from the rearrangement of β-lactam- and β-lactone-derived alkylidenecarbenes, displayed lengths intermediate between formal double and triple bonds. Furthermore, 2-(1-azacyclobutylidene)carbene was found to be nearly isoenergetic with its ring-expanded isomer, and 1-oxacyclopent-2-yne was notably higher in energy than its precursor carbene. In all other cases, the cycloalkynes were lower in energy than the corresponding carbenes. The transition states for ring-expansion were always lower for the 1,2-carbon shifts than for 1,2-nitrogen or oxygen shifts, but higher than for the 1,2-sulfur shifts. These predictions should be verifiable using carbenes bearing appropriate isotopic labels. Computed vibrational spectra for the carbenes, and their ring-expanded isomers, are presented and could be of value to matrix isolation experiments.

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Recent advances in alkylidene carbene chemistry

Cited by 48 publications

References 250 publications

Development of New Synthetic Reactions Using Hetero-Heavy Atoms and Their Application to Synthesis of Biofunctional Molecules

Development of New Synthetic Reactions Using Hetero-Heavy Atoms and Their Application to Synthesis of Biofunctional Molecules

Syntone chemistry and prebiotic stage in life evolution 1. Aziridinone, a key compound in formation of the first proteinogenic amino acids and polypeptides

Ring Expansion of Alkylidenecarbenes Derived from Lactams, Lactones, and Thiolactones into Strained Heterocyclic Alkynes: A Theoretical Study

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