513-38-2Relevant articles and documents
Visible-Light-Mediated C-I Difluoroallylation with an α-Aminoalkyl Radical as a Mediator
Yue, Fuyang,Dong, Jianyang,Liu, Yuxiu,Wang, Qingmin
supporting information, p. 7306 - 7310 (2021/10/01)
Herein, we report a protocol for direct visible-light-mediated C-I difluoroallylation reactions of α-trifluoromethyl arylalkenes with alkyl iodides at room temperature with an α-aminoalkyl radical as a mediator. The protocol permits efficient functionalization of various α-trifluoromethyl arylalkenes with cyclic and acyclic primary, secondary, and tertiary alkyl iodides and is scalable to the gram level. This mild protocol uses an inexpensive mediator and is suitable for late-stage functionalization of complex natural products and drugs.
Quinim: A New Ligand Scaffold Enables Nickel-Catalyzed Enantioselective Synthesis of α-Alkylated ?-Lactam
Chen, Yifeng,Qu, Jingping,Wu, Xianqing
supporting information, p. 15654 - 15660 (2020/10/18)
Herein, we report a nickel-catalyzed reductive cross-coupling reaction of easily accessible 3-butenyl carbamoyl chloride with primary alkyl iodide to access the chiral α-alkylated pyrrolidinone with broad substrate scope and high enantiomeric excess. The current art of synthesis still remains challenging on the enantioselective α-monoalkylation of pyrrolidinones. The newly designed chiral 8-quinoline imidazoline ligand (Quinim) is crucial for maintaining the reactivity and enantioselectivity to ensure the reductive cyclization of monosubstituted alkenes for unprecedented synthesis of chiral non-aromatic heterocycles.
Visible-Light-Promoted Remote C-H Functionalization of o-Diazoniaphenyl Alkyl Sulfones
Du, Shaofu,Kimball, Elizabeth Ann,Ragains, Justin R.
supporting information, p. 5553 - 5556 (2017/10/25)
Visible-light irradiation of ortho-diazoniaphenyl alkyl sulfones in the presence of Ru(bpy)32+ results in remote Csp3-H functionalization. Key mechanistic steps in these processes involve intramolecular hydrogen atom transfer from Csp3-H bonds to aryl radicals to generate alkyl/benzyl radicals. Subsequent polar crossover occurs by single-electron oxidation of the alkyl/benzyl radicals to carbenium ions that then intercept nucleophiles. We have developed remote hydroxylations, etherifications, an amidation, and C-C bond formation processes using this strategy.
Solvent-free, microwave-assisted conversion of tosylates into iodides
Cao, Jia,Perlmutter, Patrick
, p. 1360 - 1361 (2014/11/07)
A highly efficient method for the conversion of primary tosylates into the corresponding iodides is outlined. The method involves heating a neat mixture of the tosylate and solid sodium iodide in a microwave cavity. Reaction times are short, usually about 60 minutes, delivering high yields. This procedure is especially useful for the in situ generation of volatile primary iodides, and for most of the primary iodides, the crude product is sufficiently pure.
Sterically controlled alkylation of arenes through iridium-catalyzed C-H borylation
Robbins, Daniel W.,Hartwig, John F.
supporting information, p. 933 - 937 (2013/02/25)
Complementary chemistry: A one-pot method for the site-selective alkylation of arenes controlled by steric effects is reported. The process occurs through Ir-catalyzed C-H borylation, followed by Pd- or Ni-catalyzed coupling with alkyl electrophiles. This selectivity complements that of the typical Friedel-Crafts alkylation; meta-selective alkylation of a broad range of arenes with various electronic properties and functional groups occurs in good yield with high site selectivity. Copyright
Preparation and Characterization of [5-13C]-(2S,4R)-Leucine and [4-13C]-(2S,3S)-Valine - Establishing Synthetic Schemes to Prepare Any Site-Directed Isotopomer of L-Leucine, L-Isoleucine and L-Valine
Siebum, Arjan H. G.,Woo, Wei Sein,Lugtenburg, Johan
, p. 4664 - 4678 (2007/10/03)
In this paper a chemo-enzymatic method has been developed that gives access to any isotopomer of the essential amino acids isoleucine and valine. The method gives the correct introduction of the second chiral center in (2S,3S)-isoleucine and allows for discrimination between the two prochiral methyl groups in valine as shown by the preparation of (2S,3S)-[4- 13C] valine. For the preparation of (2S)-leucine in any isotopomeric form, the O'Donnell method to prepare optically active amino acids has been used. The protected glycine scaffold used in this method has been prepared by a strategy that allows access to any isotopomeric form. The preparation of [5-13C]-(2S,4R)-leucine shows that the O'Donnell method in combination with the Evans method to obtain chiral 2-methylpropyl iodide leads to a good discrimination between the two prochiral methyl groups. The O'Donnell strategy for the preparation of α-amino acids is preferred over other methods since the reaction conditions are mild, the chiral auxiliary can be easily recovered and the optically active product can be easily separated. For the preparation of isotopically enriched valine and isoleucine the O'Donnell method is not suitable, because the alkyl substituents involved have a secondary halide substituent which is sterically too hindered to give an effective reaction with the protected glycine. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Radical Yields in the Radiolysis of Branched Hydrocarbons: Tertiary C-H Bond Rupture in 2,3-Dimethylbutane, 2,4-Dimethylpentane, and 3-Ethylpentane
Schuler, Robert H.,Wojnarovits, Laszlo
, p. 9240 - 9247 (2007/10/03)
Gel permeation chromatography has been applied to iodine scavenging studies of the distribution of radicals produced in the radiolysis of symmetrically branched hydrocarbons 2,3-dimethylbutane, 2,4-dimethylpentane, and 3-ethylpentane. The principal iodides observed are those expected as a result of simple bond rupture. In the case of 2,3-dimethylbutane all five expected iodides are readily resolvable and it is shown that the loss of H from a tertiary position is favored over loss from a primary position by a factor of ～10. A similar ratio is also observed for 2,4-dimethylpentane. The higher ratio of 15 observed for 3-ethylpentane indicates a dependence on the number of tertiary sites on the alkane. The relative yield of ～3.3 for the loss of secondary and primary H atoms from 2,4-dimethylpentane and 3-ethylpentane is similar to that for normal alkanes, indicating a negligible effect of the adjacent tertiary carbon. In all three cases the rupture of terminal C-C bonds is relatively infrequent with C-C rupture occurring preferentially at the bonds adjacent to the tertiary carbon.
PHOTOLYSE DE HI DANS UNE MATRICE HYDROCARBONEE VITREUSE A 77 K
Laet, M. de,Tilquin, B.
, p. 97 - 105 (2007/10/02)
Stable products from the photolysis of HI in methyl-3 pentane (3 MP) or dimethyl-2,3 butane (23 DMB) quenched solid at 77 K are analyzed by capillary gas chromatography.Selective formation of a tertiary radical is proposed for the 23 DMB/HI system ; in 3 MP/HI, C-H bond rupture is also localized at the weakest tertiary bond, however the scission is not selective.
One-pot, one- and multi-carbon homologation of alkyl halides; reaction of Grignard reagents with chloroiodomethane
Hahn,Tompkins
, p. 937 - 940 (2007/10/02)
Reaction of a Grignard reagent (RMgX) with chloroiodomethane affords the corresponding iodide (RI) and, depending on R, solvent and temperature, iodides which are one-carbon and multicarbon homologs of RX. Allyl iodide but not allyl bromide can be monohomologated by the combined action of chloroiodomethane and isopropyl Grignard.
ORGANOBORANES FOR SYNTHESIS.9. RAPID REACTION OF ORGANOBORANES WITH IODINE UNDER THE INFLUENCE OF BASE. A CONVENIENT PROCEDURE FOR THE CONVERSION OF ALKENES INTO IODIDES VIA HYDROBORATION
Brown, Herbert C.,Rathke, Michael W.,Rogic, Milorad M.,de Lue, Norman R.
, p. 2751 - 2762 (2007/10/02)
The reaction of organoborane with iodine is strongly accelerated by sodium hydroxide.Organoboranes derived from terminal alkenes react with the utilization of approximately two of the three alkyl groups attached to boron, providing a maximum of 67percent yield of alkyl iodide.Thus, hydroboration-iodination of 1-decene gives a 60percent yield of n-decyl iodide.Secondary alkyl groups, derived from internal alkenes, react more sluggishly and only one of the three alkyl groups attached to boron is converted to the iodide.Thus, the procedure applied to 2-butene provides a 30percent yield of 2-butyl iodide.The use of disiamylborane bis-(3-methyl-2-butylborane, Sia2BH as hydroborating agent increases the yield of iodides from terminal alkenes since the primary alkyl groups react in preference to the secondary siamyl groups.Consequently, hydroboration of 1-decene with Sia2BH, followed by iodination gives a 95percent yield of n-decyl iodide.The use of methanolic sodium methoxide in place of sodium hydroxide provides alkyl iodides in considerably higher yields.The combination of hydroboration with iodination in the presence of a base provides a convenient method for the anti-Markovnikov hydroiodination of alkenes.The base-induced iodination of organoboranes proceeds with the inversion of configuration at the reaction center, as shown by the formation of endo-2-iodonorbornane from tri-exo-norbornylborane.
