Rhodium‐Catalyzed Hydroboration Reactions with Sulfur and Nitrogen Analogues of Catecholborane

Abstract

Rhodium-catalyzed hydroboration of 1-octene and trans-4octene with sulfur-and nitrogen analogues of catecholborane are demonstrated with the use of in situ 11 B NMR spectroscopy. Our study shows that the sulfur-and nitrogen analogues are significantly less prone to disproportionation than [a]

Solution-state 15N NMR and solid-state single-crystal XRD study of heterosubstituted diazaboroles and borinines prepared via an effective and simple microwave-assisted solvent-free synthesis

“…This could corroborate the prevailing thought that electron donation occurs from the lone pair of electrons present on nitrogen atoms to the vacant p z orbital situated on the boron atoms ( Fig. 3) [2,14,15]. This theory is further supported by DFT calculations carried out by Weber et al [16], which show orbital overlap between the nitrogen atoms and the boron atoms in the HOMO calculations for structurally similar compounds.…”

“…We also present the first X-ray crystal structure of 2-(4-Methylphenyl)-naphtho [1,8-de] [1,3,2]diazaborinine and compare it with the structures of other similar compounds determined in these laboratories.…”

“…1) have been investigated [3]. These reagents are more stable with regards to storage and handling, but are also less reactive towards olefins, requiring the use of rhodium(I)-based catalysts, such as Wilkinson's Catalyst (Rh(PPh 3 ) 3 Cl), to form the alkylated borole reagents needed for further reactions (Scheme 2), and these reactions are at present limited to the formation of terminal boron-carbon bonds [2,4]. Diazaborole reagents have been successfully used as reagents in Suzukie Miyaura reactions, but their use is limited when compared with that of the dioxoborole-based reagents [5].…”

“…These reagents have been reported to undergo disproportionation reactions (Scheme 1), resulting in lower reaction yields, and are air-and moisture-sensitive [1,2].…”

BN isosteres of indole

“…Examples include hydroboration (Scheme 9, eq 1), 27 cyanoboration (eq 2), 28 and carboboration (eq 3) 29 reactions. The 1,3,2-benzodiazaboroline substrate is a stoichiometretic reagent, ultimately forming a B-C bond in the presence of a transition metal catalyst.…”