Photochemically Induced Silylacylations of Alkynes with Acylsilanes

Abstract

Visible light initiates the stereoselective formation of two new bonds, a C À C and a C À Si bond, during the addition of acylsilanes to alkynes. At room temperature this photochemically induced transformation can be applied for the preparation of chromone derivatives in a highly atom-economic manner.

Reactions of an Isolable Dialkylsilylene with Aroyl Chlorides. A New Route to Aroylsilanes

“…Benzoylsilanes 3a-3c, which are stable thermally with definite melting points and under moist air, were characterized by 1 H-, 13 C-, and 29 Si-NMR spectroscopy, high-resolution mass spectrometry (HRMS), and X-ray structure analyses.…”

“…2.8 and 5.5 ppm) were observed in the 13 C-and 29 Si-NMR spectra of 3a-3c. The signals at 225.3 (3a), 224.5 (3b), and 224.8 (3c) ppm in 13 C-NMR spectra are ascribed to the carbonyl carbon signals, which are at higher field relative to the typical acylsilanes (ca. 240 ppm) [39,40].…”

“…Because simple alkanoyl chlorides are more reactive than aroyl chlorides, the products of the reactions between 1 and the alkanoyl chlorides may react further with 1 to give the unidentified products. (4) Benzoylsilanes 3a-3c, which are stable thermally with definite melting points and under moist air, were characterized by 1 H-, 13 C-, and 29 Si-NMR spectroscopy, high-resolution mass spectrometry (HRMS), and X-ray structure analyses.…”

“…Yellow single crystals of 3a-3c suitable for X-ray crystallography were obtained by slowly evaporating the solvent from their hexane solutions. The ORTEP drawing of compound 3a is depicted (4) Benzoylsilanes 3a-3c, which are stable thermally with definite melting points and under moist air, were characterized by 1 H-, 13 C-, and 29 Si-NMR spectroscopy, high-resolution mass spectrometry (HRMS), and X-ray structure analyses.…”

“…Acylsilanes or α-silyl ketones have been known as a unique class of silicon compounds [1][2][3][4][5][6][7][8][9], showing remarkably red-red shifted n→π* transition bands [1,2] and being useful as distinct reagents in organic synthesis [4][5][6][10][11][12][13][14][15][16][17][18][19]. Most of all, acyltris(trimethylsilyl)silanes are of particular importance, which were utilized for the synthesis of the first stable silicon-carbon doubly bonded compounds (silenes) [20,21].…”