Chemical and photochemical approaches to amino(aryl)silylenes

New Dichlorosilanes, Cyclotrisilanes, and Silacyclopropanes as Precursors of Intramolecularly Coordinated Silylenes

“…Corriu silylenes, which were supposed to be intramolecularly coordinated. [6] When treated with lithium metal or lithium naphthalenide in the presence of excess 2,3-dimethyl-1,3-butadiene, the corresponding silacyclopentenes were obtained, presumably via a coordinated silylene or silylenoid intermediate. Photolysis of tetrasilane 1 in the presence of 2,3-dimethyl-1,3-butadiene or Et 3 SiH yielded, besides hexamethyldisilane, the trapping products 3 and 6 in moderate yield.…”

“…Photolysis of tetrasilane 1 in the presence of 2,3-dimethyl-1,3-butadiene or Et 3 SiH yielded, besides hexamethyldisilane, the trapping products 3 and 6 in moderate yield. [6] However, a major drawback of this method, with regard to its synthetic utility, is the formation of appreciable amounts of tolyl-substituted silanes 4 and 5, which result from the photolytic cleavage of the benzylic C ± N bond (Scheme 2). When the photolysis of 1 was performed in a hydrocarbon matrix at À 196 8C, an intense absorption at l max 478 nm was observed, which was attributed to the intramolecularly coordinated silylene 2.…”

Theoretical Studies on the Alkylidene Silylenoid H2C = SiLiF and Its Insertion Reaction with R-H (R = F, OH, NH2)

“…5,6 Since then people tried to detect, even to obtain some silylenoid species as well as to probe into their structures and properties. [7][8][9][10][11][12][13] However, as a kind of very reactive species, the preparation of silylenoids is very difficult. Until 1995, Tamao et al 14 reported the first experimental study of silylenoid chemistry, detected the existence of [(tert-butoxy)diphenylsilyl]lithium, Ph2SiLi(OBu-t), and investigated its chemical properties.…”

Reaction of Hypercoordinate Dichlorosilanes Bearing 8-(Dimethylamino)-1-naphthyl Group(s) with Magnesium: Formation of the 1,2-Disilaacenaphthene Skeleton

“…All hydrogen atoms are omitted for clarity. Selected distances [] and angles [8]: Si1ÀSi2 2.3641(6), Si1´´´N1 3.078(2), Si2´´´N2 3.147(2), Si2´´´N3 2.970(2); O1-Si1´´´N1 168.06(6), Si2-Si1-O1 107.17(5), Si2-Si1-C1 94.35(6), Si2-Si1-C11 127.54(6), Si1-Si2´´´N2 171.97(4), N3´´´Si2-C8 175.84(7), Si1-Si2-C8 89.14(6), Si1-Si2-C26 122.15(6), Si1-Si2-C38 104.17 (6 Interestingly, in these reactions, one silicon atom became bonded to the naphthyl carbon atom that bore the amino group. The amino group migrated to the coordinated silicon atom to afford an aminosilane with a lower coordination number and was finally substituted by the isopropoxyl group during workup with isopropyl alcohol.…”

“…Thus, Corriu, Auner et al reported the reaction of a pentacoordinate difluorosilane bearing the 8-[(dimethylamino)methyl]-1-naphthyl group with lithium or lithium naphthalenide to afford a 1-silaacenaphthene derivative. [6] Both silicon ± silicon bond formation and amino-group migration proceeded concomitantly and selectively in the reaction of 1 and 3 with magnesium to afford 1-amino-1,2-disilaacenaphthene derivatives. These results indicate that the course of the reaction depends on the structure of the aminoaryl groups and suggest the possibility of developing new types of reactions by the introduction of new intramolecular coordinating groups.…”