1120-56-5Relevant articles and documents
Experimental and Theoretical Investigations of Ring-Expansion in 1-Methylcyclopropylcarbene
Thamattoor, Dasan M.,Snoonian, John R.,Sulzbach, Horst M.,Hadad, Christopher M.
, p. 5886 - 5895 (1999)
1-Methylcyclopropylcarbene, generated by photolysis of two isomeric hydrocarbon precursors, undergoes ring-expansion, readily to give 1-methylcyclobutene. Experimentally, intramolecular carbon-hydrogen insertions are not observed. Trapping studies with TME demonstrates the formation of the expected cyclopropane adduct, and via a double-reciprocal analysis, the lifetime of 1-methylcyclopropylcarbene was determined to be 12 ns in 1,1,2-trichlorotrifluoroethane. Computational studies show that the barrier to ring-expansion is significantly smaller in 1-methylcyclopropylcarbene than in cyclopropylcarbene. The origin of the increased rate of ring-expansion is due to stabilization of the positive charge that occurs at the incipient tertiary carbon that is attached to the migrating carbon center. Department of Chemistry and Biochemistry,.
Enthalpies of Hydration of Alkenes. 4. Formation of Acyclic tert-Alcohols
Wiberg, Kenneth B.,Hao, Shide
, p. 5108 - 5110 (1991)
The enthalpies of hydration of a series of acyclic alkenes that lead to tert-alcohols were determined.Several pairs of alkenes that give the same alcohol were studied and gave the differences in enthalpy of formation of the alkenes.A consistent difference in Δ Hf of 1.84 kcal/mol was found between di- and trisubstituted alkenes.It was related to the difference in Δ Hf for pairs of exocyclic and endocyclic alkenes.The enthalpies of formation of the alcohols were obtained and were related to data for primary and secondary alcohols.
Vinylcyclopropyl anion: Structure, reactivity, thermodynamic properties, and an unusual rearrangement
Guo, Hangzhou,Kass, Steven R.
, p. 1244 - 1248 (1992)
Vinylcyclopropane (1) is deprotonated in the gas phase by NH2- or Me2N to afford its conjugate base (1a). Vinylcyclopropyl anion is quite basic (ΔHacid(1) = 394 ± 3 kcal mol-1), has a relatively small electron binding energy (12 ± 5 kcal mol-1), and reacts with a variety of reagents including N2O, CS2, COS, O2, and SO2. The reaction of 1 with OH- (ΔHacid(H2O) = 390.7 kcal mol-1) leads to a surprising rearrangement and the formation of the conjugate base of methylenecyclobutane (2a). A mechanism is proposed to account for this unusual reaction and it is in accord with ab initio molecular orbital calculations. In particular, the orbital symmetry allowed (σ2s + π4s) transition state leading to 2a is slightly preferred over the conrotatory ring opening of 1a (1.2 kcal mol-1 (MP2/6-31+G*//6-31+G*)).
The non-reaction of methylene with the carbon-carbon bond
Wu, Guo-Xian,Maitland Jr., Jones,Doering, William von E.,Knox, Lawrence H.
, p. 9913 - 9920 (1997)
Methylene has been shown not to react with the carbon-carbon bonds of spiropentane and spiro[3.3]heptane.
THE 185-NM PHOTOCHEMISTRY OF 2,3-DIAZABICYCLOHEPTENE AND OF ITS DENITROGENATION PRODUCTS BICYCLOPENTANE AND CYCLOPENTENE
Adam, Waldemar,Oppenlaender, Thomas
, p. 5391 - 5394 (1982)
The 185-nm denitrogenation of 2,3-diazabicycloheptene (1) afforded bicyclo pentane (2) and cyclopentene (3) presumably via a "hot" cyclopentane-1,3-diyl diradical (8); 1,4-pentadiene (4) and methylenecyclobutane (5) were secondary products of the 185-nm photolysis of (2) and (3).
Synthesis of sp 3-Enriched β-Fluoro Sulfonyl Chlorides
Gurbanov, Rustam,Sokolov, Andriy,Golovach, Sergey,Melnykov, Kostiantyn,Dobrydnev, Alexey V.,Grygorenko, Oleksandr O.
, p. 1771 - 1784 (2020/12/28)
A three-step approach to the synthesis of sp 3-enriched β-fluoro sulfonyl chlorides starting from alkenes is reported. The method was successfully applied to a wide range of acyclic and cyclic substrates, bearing either an exocyclic or an endocyclic double bond. The procedure worked with a wide range of substrates and tolerated a number of functional and protecting groups. Moreover, the target cyclic compounds were obtained as single cis diastereomers on a multigram scale. The title compounds are promising building blocks for drug discovery that can be used to obtain sp 3-enriched β-fluoro and α,β-unsaturated sulfonamides.
PYRIDOPYRIMIDINE COMPOUNDS ACTING AS MTORC 1/2 DOUBLE-KINASE INHIBITORS
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Paragraph 0309-0311, (2020/11/30)
Disclosed are a series of pyridopyrimidine compounds and a use of same in the preparation of drugs associated with mTORC 1/2 dual complex inhibitors, and specifically disclosed is a use of the compounds as shown in formula (IV), tautomers thereof or pharmaceutically acceptable salts thereof in the preparation of drugs associated with mTORC 1/2 dual complex inhibitors.
Synthesis of energetic compounds via the metathesis reaction of 4-methylenespiro[2,3]hexane
Kotov,Chernykh,Finkel'shtein,Strel'chik,Tyshchenko,Milovantseva
experimental part, p. 309 - 313 (2010/03/24)
Transformations of methylenespiro[2,3]hexane (MSH) on a heterogeneous rhenium-alumina metathesis (disproportionation) catalyst were studied. It was found that, owing to a significant difference in the stability of carbenic complexes of methylene and disubstituted carbenes, MSH undergoes isomerization to 4-methylspiro[2,3]hex-4-ene followed by their cometathesis yielding bis(spiro[2,3]hexylidene-4). The feasibility of selective cometathesis of MSH and dicyclobutylidene on the rhenium-alumina catalyst resulting in the formation of 4-cyclobutylidenespiro[2,3]hexane was shown.
Formation of olefins upon oxidation of molybdenum alkyl carbynes. Organic radical reactivity in an organometallic radical cation
Schoch, Thomas K.,Orth, Stephen D.,Zerner, Michael C.,J?rgensen, Karl Anker,McElwee-White, Lisa
, p. 6475 - 6482 (2007/10/02)
Decomposition of the complexes (η5-C5H5)(CO){P(OMe) 3}Mo≡CR [R = C-C4H9, (CH2)3CH3, and CH(CH2-CH2CH3)2] in CHCl3 results in conversion of the carbyne ligand to a terminal olefin. The reaction is initiated by oxidation and occurs during photolysis in CHCl3 or upon slow diffusion of O2 into the reaction mixtures. Corroborating evidence for initiation of the reaction by electron transfer has been obtained by conversion of the butyl carbyne ligand of (η5-C5H5)(CO){P(OMe) 3}Mo≡C(CH2)3CH3 to 1-pentene upon electrochemical oxidation. Mechanistic studies were consistent with H-abstraction by the carbyne radical cation to yield a cationic carbene complex which forms the olefin in a H-shift process. INDO calculations on the carbyne radical cation [(η5-C5H5)(CO){P(OMe) 3}-Mo≡CCH2CH3]?+ indicate stabilization upon bending the Mo≡C-C angle from 180° to 120°. This change in geometry places spin density on the carbyne carbon in the radical cation although the initial oxidation occurs from an orbital that is primarily nonbonding metal d in character. The oxidized carbyne is thus able to function as a carbon-centered radical and abstract a hydrogen atom at the carbyne carbon. Although the olefin-forming reaction is general for alkyl carbynes with a hydrogen on C2, the tert-butyl carbyne (η5-C5H5)(CO){P(OMe) 3}Mo≡CC-(CH3)3 (2e) did not form an olefin upon oxidation. Instead, photolysis of 2e in CHCl3 yielded the dicnloromolybdenum carbyne (η5-C5H5)Cl2{P(OMe) 3}Mo≡CC(CH3)3 (5e) via a Cl-abstraction pathway.
New findings on the regiochemistry of the silylcupration of allene
Blanco,Blanco, Francisco J.,Cuadrado,Cuadrado, Purificacion,Gonzalez,Gonzalez, Ana M.,Pulido,Pulido, Francisco J.,Fleming,Fleming, Ian
, p. 8881 - 8882 (2007/10/02)
Allene 1 reacts at -40*C with the phenyldimethylsilylcopper reagent 6, with the opposite regioselectivity to that shown by the corresponding silylcuprate reagent 2, to give allylsilanes 7 and 10-15 rather than vinylsilanes.
