52152-71-3Relevant academic research and scientific papers
Heats of Formation of Some Simple Alkyl Radicals
Castelhano, A. L.,Griller, D.
, p. 3655 - 3659 (1982)
Equilibrium constants, K, for the system Me + RI MeI + R were measured in solution by using electron paramagnetic resonance spectroscopy.Given the entropies of the components of the equilibrium and the heats of formation of the iodides, the relative heats of formation of the alkyl radicals were obtained.With δHf,300(Me) = 34.4 kcal mol-1 chosen as a standard, the following heats of formation for other alkyl radicals were obtained: Et, 28.0; n-Pr, 22.8; i-Pr, 19.2; s-Bu, 13.9; c-C5H9, 25.1; t-Bu, 9.4 kcal mol-1.These data lead to the following C-H bond dissotiation energies for simple alkanes: primary C-H, ca. 100; secondary C-H, ca. 96; tertiary C-H, ca. 94 kcal mol-1.
Photoinduced Palladium-Catalyzed Dicarbofunctionalization of Terminal Alkynes
Yang, Zhen,Koenigs, Rene M.
supporting information, p. 3694 - 3699 (2021/02/01)
Herein, a conceptually distinct approach was developed that allowed for the dicarbofunctionalization of alkynes at room temperature using simple, bench-stable alkyl iodides and a second molecule of alkyne as coupling partner. Specifically, the photochemical activation of palladium complexes enabled this strategic dicarbofunctionalization via addition of alkyl radicals from secondary and tertiary alkyl iodides and formation of an intermediate palladium vinyl complex that could undergo subsequent Sonogashira reaction with a second alkyne molecule. This alkylation–alkynylation sequence allowed the one-step synthesis of 1,3-enynes including heteroarenes and biologically active compounds with high efficiency without exogenous photosensitizers or oxidants and now opens up pathways towards cascade reactions via photochemical palladium catalysis.
Visible-light-mediated multicomponent reaction for secondary amine synthesis
Wang, Xiaochen,Zhu, Binbing,Dong, Jianyang,Tian, Hao,Liu, Yuxiu,Song, Hongjian,Wang, Qingmin
supporting information, p. 5028 - 5031 (2021/05/28)
The widespread presence of secondary amines in agrochemicals, pharmaceuticals, natural products, and small-molecule biological probes has inspired efforts to streamline the synthesis of molecules with this functional group. Herein, we report an operationally simple, mild protocol for the synthesis of secondary amines by three-component alkylation reactions of imines (generated in situ by condensation of benzaldehydes and anilines) with unactivated alkyl iodides catalyzed by inexpensive and readily available Mn2(CO)10. This protocol, which is compatible with a wide array of sensitive functional groups and does not require a large excess of the alkylating reagent, is a versatile, flexible tool for the synthesis of secondary amines.
A mild and highly chemoselective iodination of alcohol using polymer supported DMAP
Das, Diparjun,H Anal, Jasha Momo,Rokhum, Lalthazuala
, p. 1695 - 1701 (2017/03/08)
The synthesis of organic compounds using polymer supported catalysts and reagents, where the required product is always in solution, has been of great interest in recent years, both in industries and academia especially in pharmaceutical research. Here, a simple and efficient method for conversion of alcohols into their iodides in high yield using polymer supported 4-(Dimethylamino)pyridine (DMAP) is described. Polymer supported DMAP is used in catalytic amount and is recovered and reused several times. Additionally, this method is highly chemoselective. [Figure not available: see fulltext.]
A transition-metal-free Heck-type reaction between alkenes and alkyl iodides enabled by light in water
Liu, Wenbo,Li, Lu,Chen, Zhengwang,Li, Chao-Jun
supporting information, p. 6170 - 6174 (2015/06/08)
A transition-metal-free coupling protocol between various alkenes and non-activated alkyl iodides has been developed by using photoenergy in water for the first time. Under UV irradiation and basic aqueous conditions, various alkenes efficiently couple with a wide range of non-activated alkyl iodides. A tentative mechanism, which involves an atom transfer radical addition process, for the coupling is proposed.
Salts of Mosher's thioacid: agents for determining the enantiomer excess of SN2 substrates
Richman, Jack E.
supporting information; experimental part, p. 2793 - 2796 (2010/07/06)
The racemic and the (S)-enantiomer of Mosher's thioacid, 2-methoxy-2-trifluoromethylphenylacetic thioacid, form air-stable salts with Proton Sponge [1,8-bis(dimethylamino)naphthalene]. These salts are powerful nucleophiles that react cleanly (SN2 inversion) in CDCl3 with optically active alkyl halides ranging in reactivities from unactivated alkyl bromides and iodides to benzylic bromides. The diastereomeric excess (de) of the thioester products indicates the enantiomeric excess (ee) of the starting alkyl halides.
Iodination of alcohols over Keggin-type heteropoly compounds: A simple, selective and expedient method for the synthesis of alkyl iodides
Rafiee, Ezzat,Mahdavia, Houri,Joshaghani, Mohammad
experimental part, p. 135 - 140 (2011/06/09)
Different catalysts derived from Keggin-type heteropoly compounds were prepared and their catalytic activities have been compared in the iodination of benzyl alcohol with KI under mild reaction conditions. A high catalytic activity was found over tungstophosphoric acid supported on silica and titania. The effect of catalyst loading, iodine source and the nature of substituents on the aromatic ring of benzyl alcohol were investigated. Finally, several competitive reactions were studied between structurally diverse alcohols. This protocol provides a mild and expedient way for the conversion of various alcohols to their corresponding alkyl iodides with high selectivity.
Mechanism of decomposition of quasiphosphonium intermediates: Borderline SN1 character of alkyl-oxygen fission in sec-alkyloxyphosphonium salts
Hudson,Qureshi
, p. 473 - 480 (2007/10/03)
Short-lived alkoxyphosphonium intermediates have been detected in the interactions of alkyl diphenylphosphinites ROPPh2 (R = Et, Pr i, Bu8, and 3-pentyl) with iodomethane at room temperature. Phosphorus chemical shifts for the sec-alkoxy(methyl) diphenylphosphonium iodides (δp 68.6-68.7 ppm) are at slightly higher field than for ethoxy(methyl)diphenylphosphonium iodide (δp 72.4 ppm), in accord with higher electron density at phosphorus in the secondary alkyl sytems. Relative rates of decomposition in CDCl3 (Me > Et > Pri ? neopentyl) are in accord with SN2-type cleavage of the R-O bond but within the secondary alkyl series the relative rates (Pri 8 N1 mechanism is proposed.
Triphenylphosphine/2,3-dichloro-5,6-dicyanobenzoquinone as a new, selective and neutral system for the facile conversion of alcohols, thiols and selenols to alkyl halides in the presence of halide ions
Iranpoor,Firouzabadi,Aghapour,Vaez zadeh
, p. 8689 - 8693 (2007/10/03)
A mixture of triphenylphosphine (Ph3P) and 2,3-dichloro-5,6-dicyanobenzoquinone in CH2Cl2 affords a complex which in the presence of R4NX (X=Cl, Br, I) converts alcohols, thiols and selenols into their corresponding alkyl halides in high yields at room temperature. The method is highly selective for the conversion of 1° alcohols in the presence of 2° ones and also 1° and 2° alcohols in the presence of 3° alcohols, thiols, epoxides, trimethylsilyl- and tetrahydropyranyl ethers, 1,3 dithianes, disulfides, and amides.
Mild conversion of alcohols to alkyl halides using halide-based ionic liquids at room temperature
Ren, Rex X.,Wu, Jeff Xin
, p. 3727 - 3728 (2007/10/03)
Formula presented Alcohols were efficiently converted to alkyl halides using 1-n-butyl-3-methylylimidazolium halides (ionic liquids) in the presence of Bronsted acids at room temperature. The alkyl halide products were easily isolated from the reaction mixture via simple decantation or extraction, and the 1-n-butyl-3-methylimidazolium cation could be recycled for further uses.
