Compared to carbon-based nucleophiles, the number of silicon-based nucleophiles that is currently available remains limited, which significantly hampers the structural diversity of synthetically accessible silicon-based molecules. Given the high synthetic utility and ease of handling of carbon-based boron nucleophiles, silicon-based boron nucleophiles, i.e., silylboranes, have received considerable interest in recent years as nucleophilic silylation reagents that are activated by transition-metal catalysts or bases. However, the range of practically accessible silylboranes remains limited. In particular, the preparation of sterically hindered and functionalized silylboranes remains a significant challenge. Here, we report the use of rhodium and platinum catalysts for the direct borylation of hydrosilanes with bis(pinacolato)diboron, which allows the synthesis of new trialkylsilylboranes that bear bulky alkyl groups and functional groups as well as new dialkylarylsilylboranes that are difficult to synthesize via conventional methods using alkali metals. We further demonstrate that these compounds can be used as silicon nucleophiles in organic transformations, which significantly expands the scope of synthetically accessible organosilicon compounds compared to previously reported methods. Thus, the present study can be expected to inspire the development of efficient methods for novel silicon-containing bioactive molecules and organic materials with desirable properties. We also report the first 11 B{ 1 H} and 29 Si{ 1 H} NMR spectroscopic evidence for the formation of i-Pr3SiLi generated by the reaction of i-Pr3Si-B(pin) with MeLi.

Carbon-nitrogen (C-N) bond-forming cross-coupling reactions catalyzed by palladium-based catalysts, the socalled Buchwald-Hartwig aminations, have been widely employed for the synthesis of pharmaceuticals and aryl-amine-based organic materials in academic and industrial settings. However, in solution, these reactions usually require glove-box and Schlenk-line techniques, which greatly reduces their practical utility. Here, we report the development of operationally simple mechanochemical C-N cross-coupling reactions in the solid-state. Intensive investigations of various ball milling parameters revealed that the air-stable ligand tri(1-adamantyl)phosphine can be used to achieve solid-state coupling reactions between aryl halides and diarylamines with high efficiency. Notably, all experimental operations of the developed protocol can be carried out in air, thus providing a more convenient, industrially attractive, and sustainable alternative to conventional solution-based palladium-catalyzed C-N coupling reactions.

The Suzuki–Miyaura cross-coupling between polyfluorinated arylboron nucleophiles and aryl halides enables the efficient construction of polyfluorinated structural motifs frequently found in organic materials and catalysts. A key challenge associated with this transformation involves the slow transmetalation with weakly nucleophilic polyfluorinated organoboron reagents, which often reduces the yield of the coupling products. Here, we show that solid-state high-temperature ball-milling conditions facilitate a palladium-catalyzed cross-coupling with polyfluorinated arylboronic acids and pinacol esters employing a simple catalytic system in the absence of any stoichiometric additives. This reaction exhibits a broad substrate scope and can be carried out in air, and the use of large amounts of dry and degassed organic solvents is not required. The successful cross-coupling of weakly nucleophilic polyfluorinated organoboron reagents was ascribed to the extremely high concentrations of the substrates and the catalyst under solid-state conditions.

Silylative dearomatizations of indole-2-carboxylates were accomplished using a copper(I) catalyst and silylboronates. This reaction presumably proceeds through regioselective addition of silylcopper(I) species to indole substrates followed by highly diastereoselective protonation of the resulting copper(I) enolate intermediates to afford the corresponding dearomative silylation products. The first silylative dearomatization of pyrroles using the developed catalytic system is also described.

Page 14125. The authors regret that the pioneering study on the use of silylboronates in organic synthesis reported by Suginome and Ito in 1996 1 was not mentioned in the original manuscript. The third sentence of the second paragraph in the introduction part should be revised to read as follows: "Since the pioneering study of Suginome and Ito in 1996, silylboranes have been widely employed as useful reagents for the transition-metal-or base-catalyzed nucleophilic introduction of silyl groups into organic molecules." This revision does not affect the results or conclusions of the original manuscript.