Direct Dehydrogenative Coupling of Alcohols with Hydrosilanes Promoted by Sodium tri(sec-butyl)borohydride

Abstract

Alkoxysilanes find application in many areas of chemistry ranging from research-scale organic synthesis to multi-ton production of materials. Classically, they are obtained in stoichiometric reaction of alcoholysis of chlorosilanes, however, recent years brought development in the field of direct dehydrogenative coupling of hydrosilanes with alcohols, which is a more atom-economic and benign alternative to the former process. In this paper, we report the use of sodium tri(sec-butyl)borohydride as a convenient promoter of this reaction. Exemplary syntheses carried out under mild conditions and without additional solvents, followed by very easy work-up procedure, show excellent potential for application of so devised catalytic system.

Chemical and Redox Noninnocence of Pentane-2,4-dione Bis(S-methylisothiosemicarbazone) in Cobalt Complexes and Their Application in Wacker-Type Oxidation

“…While the former two resonances disappeared over time, the third signal reached maximal intensity after the first two species had disappeared completely. These time-dependent spectra mirror the consecutive dehydrogenative coupling of PhSiH 3 with MeOH- d 4 mentioned in many other catalytic studies. ,,,− Stepwise formation of PhSiH 2 (OCD 3 ), PhSiH­(OCD 3 ) 2 , and PhSi­(OCD 3 ) 3 in the presence of 2 was confirmed by the measurement of the 29 Si signal of PhSi­(OCH 3 ) 3 and compared with the time-independent spectra of PhSiH 3 measured in the absence of 2 (see Figure S81). It is worth noting that Ph­( i -Pr–O)­SiH 2 has been found to be an exceptionally efficient reductant in catalytic reactions, with detailed mechanistic pictures of such transformations recently reported …”

Silylation of Alcohols, Phenols, and Silanols with Alkynylsilanes – an Efficient Route to Silyl Ethers and Unsymmetrical Siloxanes

“…[6][7][8][9][10] to their most known function as a temporary protective group for hydroxyl moieties (e.g., natural products synthesis, derivatization, etc.). [11][12][13][14] There are several methods of their synthesis, starting with classical condensation between alcohols and halosilanes, [15] and finishing on catalytic coupling reactions with hydro-, [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] vinyl- [33] or allylsilanes, [34,35] and more recently also with silyl formates. [36][37][38] However, in the case of O-silylation of alcohols with alkynylsilanes -this process has never been comprehensively studied, and previous investigations have mainly referred to the problem of C sp -Si bond stability rather than the application of this transformation as an efficient method for obtaining silyl ethers.…”

Synthesis of Alkynylsilanes: A Review of the State of the Art

“…This NaH species then engaged with the alkyne, yielding sodium acetylide along with the liberation of molecular hydro- drides to encompass the dehydrogenative coupling reaction of alcohols, ultimately yielding silyl ethers. [115] Subsequently, Prabusankar employed copper(I) complexes supported by NHC=S ligands (Figure 22). [116] The optimized conditions included the use of 1 mol% of the catalyst in acetonitrile at 100 °C.…”