We report here a new method for the synthesis of organohydrosilanes from phenols and ketones. This method is established through reductive C−Si coupling of chlorohydrosilanes via unconventional Si−Cl cleavage. The reaction offers access to aryl‐ and alkenylhydrosilanes with a scope that is complementary to those of the established methods. Electron‐rich, electron‐poor, and ortho‐/meta‐/para‐substituted (hetero)aryl electrophiles, as well as cyclic and acyclic alkenyl electrophiles, were coupled successfully. Functionalities, including Grignard‐sensitive groups (e.g., primary amine, amide, phenol, ketone, ester, and free indole), acid‐sensitive groups (e.g., ketal and THP protection), alkyl‐Cl, pyridine, furan, thiophene, Ar‐Bpin, and Ar‐SiMe3, were tolerated. Gram‐scale reaction, incorporation of ‐Si(H)R2 into complex biologically active molecules, and derivatization of formed organohydrosilanes are demonstrated.
The regiocontrolled functionalization
of 1,3-dienes has become
a powerful tool for divergent synthesis, yet it remains a long-standing
challenge for aliphatic substrates. Herein, we report a reductive
approach for a branch-selective 1,2-hydrovinylation of aliphatic 1,3-dienes
with R–X electrophiles, which represents a new selectivity
pattern for diene functionalization. Simple butadiene, aromatic 1,3-dienes,
and highly conjugated polyene were also tolerated. The combination
of Ni(0) and the phosphine–nitrile ligand generally resulted
in >20:1 regioselectivity with the retention of the geometry of
the
C3–C4 double bonds. This reaction proceeds
with a broad substrate scope, and it allows for the conjugation of
two biologically active units to form more complex polyene molecules,
such as tetraene and pentaene as well as heptaene.
We report here a new method for the synthesis of organohydrosilanes from phenols and ketones. This method is established through reductive CÀ Si coupling of chlorohydrosilanes via unconventional SiÀ Cl cleavage. The reaction offers access to aryl-and alkenylhydrosilanes with a scope that is complementary to those of the established methods. Electron-rich, electron-poor, and ortho-/meta-/para-substituted (hetero)aryl electrophiles, as well as cyclic and acyclic alkenyl electrophiles, were coupled successfully. Functionalities, including Grignard-sensitive groups (e.g., primary amine, amide, phenol, ketone, ester, and free indole), acid-sensitive groups (e.g., ketal and THP protection), alkyl-Cl, pyridine, furan, thiophene, Ar-Bpin, and Ar-SiMe 3 , were tolerated. Gram-scale reaction, incorporation of -Si(H)R 2 into complex biologically active molecules, and derivatization of formed organohydrosilanes are demonstrated.
Transition-metal-catalyzed
sila-cycloaddition has been a promising
tool for accessing silacarbocycle derivatives, but the approach has
been limited to a selection of well-defined sila-synthons. Herein,
we demonstrate the potential of chlorosilanes, which are industrial
feedstock chemicals, for this type of reaction under reductive nickel
catalysis. This work extends the scope of reductive coupling from
carbocycle to silacarbocycle synthesis and from single C–Si
bond formation to sila-cycloaddition reactions. The reaction proceeds
under mild conditions and shows good substrate scope and functionality
tolerance, and it offers new access to silacyclopent-3-enes and spiro
silacarbocycles. The optical properties of several spiro dithienosiloles
as well as structural variations of the products are demonstrated.
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