LAH, Lithium aluminum hydride, Lithium tetrahydridoaluminate
LiAlH4 is a very common, strong reducing agent, which reduces a vast number of different functional groups.
Recent Literature
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.
A tethered alkene functionality can be used as a traceless directing group
for a zirconium catalyzed reductive cleavage of Csp3 and Csp2
carbon-heteroatom bonds, including C-O, C-N, and C-S bonds. The reaction is
especially useful for cleavage of homoallylic ethers and the removal of terminal
allyl and propargyl groups.
C. Matt, F. Kölblin, J. Streuff,
Org. Lett., 2019, 21, 6909-6913.
Secondary α-chloroketimines react with lithium aluminium hydride in ether to
afford mixtures of cis- and trans-1,2,3-trisubstituted aziridines
by nucleophilic addition of hydride across the imino bond and subsequent
intramolecular nucleophilic substitution. Tertiary α-chloroketimines react
similarly to yield 1,2,2,3-tetrasubstituted aziridines. α,α-Dichloroketimines
react in a stereospecific way to afford cis-aziridines, exclusively.
N. De Kimpe, L. Moens, Tetrahedron, 1990,
46, 2965-2974.
Various phosphine oxides are efficiently reduced by the use of a methylation
reagent, followed by lithium aluminum hydride. Optically active P-chirogenic
phosphine oxides are reduced with inversion of configuration.
T. Imamoto, S.-i. Kikuchi, T. Miura, Y. Wada,
Org. Lett., 2001, 3, 87-90.
Phenol carbamates undergo an anionic ortho-Fries rearrangement to
their corresponding amides in the presence of LDA. Sterically hindered
substrates can be converted with s-BuLi/TMEDA at -90°C. The amides can be efficiently reduced with lithium aluminum hydride
to the corresponding Mannich bases.
N. Assimomytis, Y. Sariyannis, G. Stavropoulos, P. G. Tsoungas, G. Varvounis, P.
Cordopatis, Synlett, 2009,
2777-2782.
Trifluoromethyl arenes were reduced with lithium aluminum hydride to give
toluene derivatives in good yields in the presence of 5 mol % of niobium(V)
chloride. Stepwise, partial reduction of a bis(trifluoromethyl) arene was
also demonstrated.
K. Fuchibe, Y. Ohshima, K. Mitomi, T. Akiyama, Org. Lett., 2007,
9, 1497-1499.
Treatment of substituted arylbromides with tert-butyllithium in diethyl
ether at -78˚C, followed by the addition to dichlorodiethoxysilane, leads to the
quantitative formation of diaryldiethoxysilanes. Diaryldiethoxysilanes can be
reduced to the corresponding diarylsilanes by stirring with lithium aluminum
hydride in diethyl ether. This method avoids the handling of gaseous and
explosive dichlorosilane.
P. Gigier, W. A. Herrmann, F. E. Kühn, Synthesis, 2010,
1431-1432.
A stereoselectiv hydrodefluorination reaction of trifluoromethylated alkenes
with LiAlH4 provides terminal monofluoroalkenes in very good yields
and diastereoselectivities. Mechanistic studies suggested a hydroalumination
reaction followed by a stereoselective fluoride elimination.
P. Poutrel, X. Pannecoucke, P. Jubault, T. Poisson,
Org. Lett., 2020, 22, 4858-4863.
