Categories: C-Si Bond Formation, C-B Bond Formation >
Synthesis of 1,1-silylboranes and silylboronates
Reactions
Enantioenriched 1,1-silylboryl alkanes are highly valued building blocks in asymmetric
synthesis as well as medicinal chemistry. An enantioselective cobalt-catalyzed hydrosilylation/hydroboration
cascade of terminal alkynes offers chemo-, regio-, and stereoselectivity exquisitely controlled by a single
set of metal catalyst and ligand.
S. Jin, K. Liu, S. Wang, Q. Song, J. Am. Chem. Soc.,
2021, 143, 13124-13134.
Enantioenriched 1,1-silylboryl alkanes are highly valued building blocks in asymmetric
synthesis as well as medicinal chemistry. An enantioselective cobalt-catalyzed hydrosilylation/hydroboration
cascade of terminal alkynes offers chemo-, regio-, and stereoselectivity exquisitely controlled by a single
set of metal catalyst and ligand.
S. Jin, K. Liu, S. Wang, Q. Song, J. Am. Chem. Soc.,
2021, 143, 13124-13134.
A convenient method for the synthesis of 1,1-diboronates from the corresponding
N-tosylhydrazones is also applicable to 1-silyl-1-boron compounds.
Derivatization and consecutive Pd-catalyzed cross-coupling reactions with
1,1-boronates were also explored, demonstrating the synthetic potential of
1,1-diboronates.
H. Li, X. Shangguan, Z. Zhang, S. Huang, Y. Zhang, J. Wang, Org. Lett., 2014,
16, 448-451.
A base-mediated borylsilylation of benzylic ammonium salts provides geminal
silylboronates bearing benzylic proton under mild reaction conditions.
Deaminative silylation of aryl ammonium salts was also achieved in the presence
of LiOtBu. Both methods offer high efficiency, mild reaction conditions,
and good functional group tolerance for late-stage functionalization of amines.
W.-Y. Qi, J.-S. Zhen, X.-h. Xu, X. Du, Y.-h. Li, H. Yuan, Y.-S. Guan, X. Wei,
Z.-Y. Wang, G. Liang, Y. Luo, Org. Lett., 2021, 23,
5988-5992.
Boryl cyclopropenes can be used as precursors for the swift synthesis of
α-boryl metal carbenes, a powerful category of intermediates for chiral
organoboron synthesis. These α-boryl carbenes undergo a series of highly
enantioselective transfer reactions, including B-H and Si-H insertion,
cyclopropanation, and cyclopropanation/Cope rearrangement, catalyzed by a
singular chiral copper complex.
M.-Y. Huang, J.-B. Zhao, C.-D. Zhang, Y.-J. Zhou, Z.-S. Lu, S.-F. Zhu, J. Am. Chem. Soc.,
2024, 146, 9872-9879.
Related
A (diiodo(trimethylsilyl)methyl)boronic ester was synthesized in a 4-step
sequence using inexpensive and commercially available starting materials. The
use of this carbene precursor in an organocatalyzed and visible light mediated
borosilylcyclopropanation of styrene provides 1,1,2-tri- and
1,1,2,2-tetrasubstituted borosilylcyclopropanes in excellent yields and
diastereoselectivity.
L. Thai-Savard, M. Sayes, J. Perreault-Dufour, G. Hong, L. A. Wells, M. C.
Kozlowski, A. B. Charette, J. Org. Chem., 2023, 88,
1515-1521.