- Nickel-catalyzed Negishi cross-couplings of secondary nucleophiles with secondary propargylic electrophiles at room temperature
-
(Chemical Equation Presented) Mild thing: The first nickel-based catalysts for cross-couplings of secondary organometallic nucleophiles with secondary alkyl electrophiles have been developed. Thus, Negishi reactions proceed under mild conditions (at room temperature with no basic activators) in the presence of NiCl2·glyme and a tridentate ligand (see scheme).
- Smith, Sean W.,Fu, Gregory C.
-
supporting information; experimental part
p. 9334 - 9336
(2009/05/16)
-
- NaIO4-KI-NaN3 as a new reagent system for C-H functionalization in hydrocarbons
-
The NaIO4-KI-NaN3 combination has been found to be an efficient, reliable, and inexpensive reagent system for mono- and 1,2-difunctionalization of hydrocarbons via C-H bond activation to afford vicinal azido- and acetoxy iodinations of cyclic hydrocarbons.
- Chouthaiwale, Pandurang V.,Suryavanshi, Gurunath,Sudalai, Arumugam
-
scheme or table
p. 6401 - 6403
(2009/04/06)
-
- Mechanism of decomposition of quasiphosphonium intermediates: Borderline SN1 character of alkyl-oxygen fission in sec-alkyloxyphosphonium salts
-
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.
- Hudson,Qureshi
-
p. 473 - 480
(2007/10/03)
-
- Direct bromination and iodination of non-activated alkanes by hypohalite reagents
-
The direct functionalisation of alkanes through bromination and iodination has been successfully achieved. The combination of stoichiometric mixtures of elemental halogen and sodium alkoxides leads to the formation of alkyl hypobromites and hypoiodites as reagents. The halogenation occurs without external photostimulation under thermal reaction conditions. Georg Thieme Verlag Stuttgart.
- Montoro, Raul,Wirth, Thomas
-
p. 1473 - 1478
(2007/10/03)
-
- New iodination reactions of saturated hydrocarbons
-
Unactivated C-H bonds react with iodine when exposed to trimethylsilyl azide in the presence of a hypervalent iodine reagent or, alternatively, to aqueous H2O2, acetic anhydride, and sodium azide (see scheme). (Chemical Equation Presented).
- Barluenga, Jose,Campos-Gomez, Esther,Rodriguez, David,Gonzalez-Bobes, Francisco,Gonzalez, Jose M.
-
p. 5851 - 5854
(2007/10/03)
-
- Cross-Couplings of Unactivated Secondary Alkyl Halides: Room-Temperature Nickel-Catalyzed Negishi Reactions of Alkyl Bromides and Iodides
-
The development of a nickel- or palladium-catalyzed method for cross-coupling unactivated secondary alkyl halides has been a long-standing challenge in synthetic chemistry. This communication describes a simple catalyst system-Ni(cod)2/s-Bu-Pybox-that achieves room-temperature Negishi reactions of an array of functionalized primary and secondary alkyl bromides and iodides. Copyright
- Zhou, Jianrong,Fu, Gregory C.
-
p. 14726 - 14727
(2007/10/03)
-
- Direct Iodination of Alkanes
-
(Matrix presented) A cheap and efficient iodination of hydrocarbons can be achieved by generating tert-butyl hypoiodite from iodine and sodium tert-butoxide. The alkane is reactant and solvent, and this metal-free process provides a clean solution for their direct iodination.
- Montoro, Raul,Wirth, Thomas
-
p. 4729 - 4731
(2007/10/03)
-
- First examples of superelectrophile initiated iodination of alkanes and cycloalkanes
-
Direct iodination of alkanes and cycloalkanes in the presence of superelectrophiles has been accomplished for the first time. The reactions of saturated hydrocarbons with I2 in the presence of CCl4·2AlI3 at -20°C afforded monoiodides in good yields and selectivities.
- Akhrem, Irena,Orlinkov, Alexander,Vitt, Sergei,Chistyakov, Anatolii
-
p. 1333 - 1335
(2007/10/03)
-
- The first efficient iodination of unactivated aliphatic hydrocarbons
-
No heavy metals, no enzymes, and a simple protocol: the direct iodination of aliphatic hydrocarbons, which has not been possible to date, can now be carried out in multiphase systems [see for example Eq. (l)]. In situ generated tetraiodomethane serves as a key intermediate in this selective radical chain reaction initiated by a single electron transfer. This room-temperature, efficient transformation is highly regioselective, easy to work-up, and hence widely applicable.
- Schreiner, Peter R.,Lauenstein, Oliver,Butova, Ekaterina D.,Fokin, Andrey A.
-
p. 2786 - 2788
(2007/10/03)
-