Categories: C-Br Bond Formation >
Synthesis of alkyl bromides
Name Reactions
Recent Literature

Nucleophilic fluorination using CsF or alkali metal fluorides was completed in
short reaction time in the presence of [bmim][BF4] affording the
desired products without any byproducts. Facile nucleophilic substitutions such
as halogenations, acetoxylation, nitrilation, and alkoxylations in the presence
of ionic liquids provided the desired products in good yields.
D. W. Kim, C. E. Song, D. Y. Chi, J. Org. Chem., 2003, 68,
4281-4285.

Silicaphosphine (Silphos), [P(Cl)3−n(SiO2)n] is a new
heterogeneous reagent that converts alcohols and thiols to their corresponding
bromides and iodides in the presence of molecular halogen in refluxing CH3CN
in high to quantitative yields. Separation of the Silphos oxide byproduct can be
achieved by a simple filtration.
N. Iranpoor, H. Firouzabadi, A. Jamalian, F. Kazemi, Tetrahedron, 2005,
61, 5699-5704.

In a triphasic phase-vanishing system comprised of an alkane, perfluorohexanes,
and bromine, photoirradiation efficiently generate hydrogen bromide, which
underwent radical addition with 1-alkenes in the hydrocarbon layer to afford
terminal bromides in high yields.
H. Matsubara, M. Tsukida, D. Ishihara, K. Kuniyoshi, I. Ryu, Synlett, 2010,
2014-2018.

A bromide Vilsmeier reagent promotes the conversion of primary alkyl
dimethylthiocarbamates into alkyl bromides in high yields in the presence of
other non-acid sensitive and non-nucleophilic functional groups.
M. F. Moynihan, J. W. Tucker, C. J. Abelt, Synthesis, 2008,
3565-3568.

The preparation of alkenyl halides of any length from inexpensive starting
reagents is reported. Standard organic transformations were used to prepare
straight-chain α-olefin halides in excellent overall yields with no
detectable olefin isomerization and full recovery of any unreacted starting
material.
T. W. Baughman, J. C. Sworen, K. B. Wagener, Tetrahedron, 2004,
60, 10943-10948.

An efficient conversion of alcohols and β-amino alcohols to the corresponding
chlorides can be carried out at room temperature in methylene
chloride, using 2,4,6-trichloro[1,3,5]triazine and N,N-dimethyl formamide.
Addition of NaBr allows the synthesis of bromides. Optically active carbinols
react under inversion.
L. de Luca, G. Giacomelli, A. Porcheddu, Org. Lett., 2002,
4, 553-555.

Halofluorination of alkenes in the presence of trihaloisocyanuric acids and HF•pyridine
results in the formation of vicinal halofluoroalkanes in good yields. The
reaction is regioselective leading to Markovnikov-oriented products and the
halofluorinated adducts follow anti-addition in the case of cyclohexene
and 1-methylcyclohexene.
L. T. C. Crespo, R. da S. Ribeiro, M. S. S. de Mattos, P. M. Esteves, Synthesis, 2010,
2379-2382.

Sm(OTf)3 is an effective catalysts for a versatile and efficient
halogen-promoted highly regio- and stereoselective Friedel-Crafts (F-C)
alkylation of electron-rich arenes with alkenes and α,β-unsaturated carbonyl
compounds in the presence of NBS or I2 as halogen sources.
S. Haira, B. Maji, S. Bar, Org. Lett., 2007,
9, 2783-2786.

C. Ye, J. M. Shreeve, J. Org. Chem.,
2004,
69, 8561-8563.

Unsaturated compounds such as alkenes, alkynes, allenes, and
methylenecyclopropanes (MCPs) can be dibrominated within minutes by NBS and
lithium bromide in THF at room temperature in good to excellent yields under
mild conditions.
L.-X. Shao, M. Shi, Synlett,
2006, 1269-1271.


