Diethoxymethylsilane, DEMS
see also: dimethoxymethylsilane
Recent Literature
Chiral rhodium-bis(oxazolinyl)phenyl complexes catalyze the conjugate
hydrosilylation of 3,3-diarylacrylate derivatives to prepare optically active
3,3-diarylpropanoate derivatives in high yields and high enantioselectivities.
K. Itoh, A. Tsuruta, J.-i. Ito, Y. Yamamoto, H. Nishiyama, J. Org. Chem., 2012,
77, 10914-10919.
Selective conjugate reductions of α,β-unsaturated aldehydes were achieved in the
presence of rhodium(bisoxazolinylphenyl) complexes as catalysts and
alkoxyhydrosilanes as reducing agents.
Y. Kanazawa, H. Nishiyama, Synlett, 2006,
3343-3345.
In a Pd(II)-catalyzed enantioselective Markovnikov hydrooxygenation of
unactivated terminal alkenes using a substituted pyridinyl oxazoline (Pyox)
ligand, a (EtO)2MeSiH/BQ redox system is vital for the highly
selective and efficient hydrooxygenation. This method provides efficient access
to a broad range of optically pure alcohol esters from easily available alkenes
with excellent enantioselectivities.
X. Yang, X. Li, P. Chen, G. Liu, J. Am. Chem. Soc.,
2022, 144, 7972-7977.
A nickel-catalyzed, multicomponent regio- and enantioselective
hydroformylation and carbonylation using chloroformate as a safe CO source
provides a wide variety of unsymmetrical dialkyl ketones bearing a
functionalized α-stereocenter, including enantioenriched chiral α-aryl ketones
and α-amino ketones.
J. Chen, S. Zhu, J. Am. Chem. Soc.,
2021, 143, 14089-14096.
A sterically encumbered bis(oxazoline) ligand backbone enables a Ni-catalyzed enantioselective deaminative alkylation of amino acid and
peptide derivatives with unactivated olefins. This protocol is distinguished by its broad scope and
generality across a wide number of counterparts, even in the context of
late-stage functionalization.
S.-Z. Sun, Y.-M. Cai, D.-L. Zhang, J.-B. Wang, H.-Q. Yao, X.-Y. Rui, R.
Martin, M. Shang, J. Am. Chem. Soc.,
2022, 144, 1130-1137.
Treatment of β,β-disubstituted-α,β-unsaturated ketones bearing a ketone residue
with in situ generated, catalytic CuH ligated by a nonracemic ligand leads to
cyclic aldol products with three newly created adjacent chiral centers.
Excellent diastereoselectivities and enantioselectivities are obtained for
several examples studied.
B. H. Lipshutz, B. Amorelli, J. B. Unger, J. Am. Chem. Soc., 2008,
130, 14378-14379.
A CuH-catalyzed hydroamination of alkenes using an amine transfer reagent and a
silane provides chiral amines with high efficiency and stereoselectivity.
However, the current technology has been limited to dialkylamine transfer
reagents (R2NOBz). A modified type of monoalkylamine transfer enabled
the synthesis of chiral secondary amines, including those derived from amino
acid esters, carbohydrates, and steroids.
D. Niu, S. L. Buchwald, J. Am. Chem. Soc., 2015,
137, 9716-9721.
A highly enantio- and regioselective copper-catalyzed hydroamination reaction of
alkenes with hydroxylamine esters in the presence of diethoxymethylsilane
enables the conversion of a wide variety of substituted styrenes, including
trans-, cis-, and β,β-disubstituted styrenes, to yield α-branched
amines. In addition, aliphatic alkenes gave exclusively the anti-Markovnikov
hydroamination products.
S. Zhu, N. Niljianskul, S. L. Buchwald, J. Am. Chem. Soc., 2013,
135, 15746-15749.
S. Zhu, N. Niljianskul, S. L. Buchwald, J. Am. Chem. Soc., 2013,
135, 15746-15749.
In a ligand-controlled cobalt-catalyzed regiodivergent alkyne hydroalkylation
of terminal alkynes with alkyl halides, use of bisoxazoline and
pyridine-oxazoline ligands provided (E)-1,2-disubstituted and
1,1-disubstituted alkenes with high E/Z stereoselectivity and
regioisomeric ratio. Internal alkynes provide trisubstituted alkenes. The
methods show excellent functional group compatibility.
Y. Li, D. Liu, L. Wan, J.-Y. Zhang, X. Lu, Y. Fu, J. Am. Chem. Soc.,
2022, 144, 13961-13972.
In a ligand-controlled cobalt-catalyzed regiodivergent alkyne hydroalkylation
of terminal alkynes with alkyl halides, use of bisoxazoline and
pyridine-oxazoline ligands provided (E)-1,2-disubstituted and
1,1-disubstituted alkenes with high E/Z stereoselectivity and
regioisomeric ratio. Internal alkynes provide trisubstituted alkenes. The
methods show excellent functional group compatibility.
Y. Li, D. Liu, L. Wan, J.-Y. Zhang, X. Lu, Y. Fu, J. Am. Chem. Soc.,
2022, 144, 13961-13972.
A nickel-catalyzed hydrotrifluoroalkylation of terminal alkynes provides
allylic trifluoromethyl terminal alkenes with high efficiency, broad substrate
scope, and favorable functional group compatibility. The combination of nitrogen
and phosphine ligands, especially electron-rich ones, plays an indispensable
role in the course of the reaction.
T. Zhang, Y.-W. Zuo, R.-X. Jin, Y.-F. Zhang, B.-B. Wu, X.-S. Wang, Org. Lett., 2023, 25,
3578-3584.
Unprecedented chemoselective reductions of phosphine oxides to phosphines
with inexpensive silanes proceed smoothly in the presence of catalytic amounts
of specific phosphoric acid esters. The reaction tolerates ketones, aldehydes,
olefins, nitriles, and esters under the optimized conditions.
Y. Li, L.-Q. Lu, S. Das, S. Pisiewicz, K. Junge, M. Beller, J. Am. Chem. Soc., 2012,
134, 18325-18329.
A Ni-H-catalyzed hydroalkylation of vinylsilanes and -germanes as well as
allylsilanes with unactivated alkyl iodides proceeds with anti-Markovnikov
selectivity to deliver the linear regioisomer. Mechanistic control experiments
support a radical mechanism, and a competition experiment reveals that the
chemoselectivity is in favor of the vinyl over the allyl group.
D. Brösamlen, M. Oestreich, Org. Lett., 2023, 25,
5319-5323.
Enantioenriched CN-containing all-carbon quaternary stereocenters can be
assembled by desymmetrizing cyclization of aryl/alkenyl halide-tethered
malononitriles. The use of a silane reductant is crucial to the
enantioselectivity and reactivity.
Z.-H. Chen, R.-Z. Sun, F. Yao, X.-D. Hu, L.-X. Xiang, H. Cong, W.-B. Liu, J. Am. Chem. Soc.,
2022, 144, 4776-4782.
A diastereo- and enantioselective CuH-catalyzed method for the preparation of
highly functionalized indolines offers mild reaction conditions and high degree
of functional group compatibility. This method is highly valuable for the
synthesis various cis-2,3-disubstituted indolines in high yield and
enantioselectivity.
E. Ascic, S. L. Buchwald, J. Am. Chem. Soc., 2015,
137, 4666-4669.