Enantioselective Intermolecular C−H Silylation of Heteroarenes for the Synthesis of Acyclic Si‐Stereogenic Silanes

Abstract

Intermolecular C−H silylation for the synthesis of acyclic silanes bearing a silicon‐stereogenic center in one enantiomeric form remains unknown to date. Herein, we report the first enantioselective intermolecular C−H silylation of heteroarenes for the synthesis of acyclic silicon‐stereogenic heteroarylsilanes. This process undergoes a rhodium‐catalyzed direct intermolecular dehydrogenative Si−H/C−H cross‐coupling, giving access to a variety of acyclic heteroarylated silicon‐stereogenic monohydrosilanes, including bis‐Si‐stereogenic silanes, in decent yields with excellent chemo‐, regio‐, and stereo‐control, which significantly enlarge the chemical space of the optically active silicon‐stereogenic monohydrosilanes.

Silicon‐Stereogenic Monohydrosilane: Synthesis and Applications

“…[47] Very recently, this SiÀ H/C(sp 2 )À H dehydrogenative coupling reaction has been realized in an intermolecular manner by the C. He group (Scheme 27). [48] By using [Rh(COD)Cl] 2 /(R,S p )-Josiphos/NBE-OMe conditions, the acyclic silanes containing two Si-stereogenic centers were accessible from a dehydrogenative coupling reaction between dihydrosilane 39 and heterocycle 40. The authors also showcased the reaction with substituted (hetero)arenes, which gave the corresponding mono-Si-stereogenic product (Si-31 c) in excellent regioselectivity and high enantioselectivity.…”

“…In 1959, Sommer and Frye reported the chlorination of chiral monohydrosilane ( si R)-Si-1 by using chlorine as the halide source to give the corresponding product 1 with retention of the configuration (Scheme 34). [8] Later, a series of optically active silane derivatives were synthesized by the same research group from Si-1, including silylbromide (47), alkylsilane (48), benzylsilane (49), and allylsilane ( 50), with the last three obtained with organolithium reagents. [13,60] Carbene insertion into an SiÀ H bond has been demonstrated to be an efficient method for the construction of tetrasubstituted silanes.…”

Silicon‐Stereogenic Monohydrosilane: Synthesis and Applications

“…Very recently, this Si−H/C(sp 2 )−H dehydrogenative coupling reaction has been realized in an intermolecular manner by the C. He group (Scheme 27). [48] By using [Rh(COD)Cl] 2 /( R , S p )‐Josiphos/NBE‐OMe conditions, the acyclic silanes containing two Si‐stereogenic centers were accessible from a dehydrogenative coupling reaction between dihydrosilane 39 and heterocycle 40 . The authors also showcased the reaction with substituted (hetero)arenes, which gave the corresponding mono‐Si‐stereogenic product ( Si‐31 c ) in excellent regioselectivity and high enantioselectivity.…”

A direct method to access various functional arylalkoxysilanes by Rh-catalysed intermolecular C–H silylation of alkoxysilanes

“…Since the pioneering work by the Curtis group in 1982, 5 a series of reports on C–H silylations have been published by many research groups (Scheme 1A). 6–11 This seemingly well-established area, however, is still too far from industrial applications because the C–H silylation reactions developed so far are mostly with highly reactive trialkylsilanes to afford trialkylarylsilanes ( i.e. , mostly Et 3 SiAr), which are unable to be utilized as monomers/reagents in silicone material synthesis due to the lack of leaving groups.…”