Synthesis of Nitrile Derivatives of the closo-Decaborate and closo-Dodecaborate Anions [BnHn – 1NCR]– (n = 10, 12) by a Microwave Method

Nucleophilic addition reactions to nitrilium derivatives [B12H11NCCH3]− and [B12H11NCCH2CH3]−. Synthesis and structures of closo-dodecaborate-based iminols, amides and amidines

“…Recently, the microwave radiation assisted synthesis of the tetrabutylammonium salts of the nitrilium derivatives of closo-dodecaborate anion [B 12 H 11 NuCMe](NBu 4 ) and [B 12 H 11 NuCEt](NBu 4 ) has been proposed, however the product yields have not been reported. 36 We modified the method and found that the title nitrilium compounds [B 12 H 11 NuCR] − (R = Me, Et) can be synthesized from the readily available triethylammonium salt of the closo-dodecaborate anion [B 12 H 12 ](NHEt 3 ) 2 (Scheme 1). Brief heating at reflux of a solution of the parent closo-dodecaborate in an appropriate nitrilium solvent in the presence of trifluoroacetic acid and trifluoroacetic anhydride results in the formation of the corresponding nitrilium derivatives [B 12 H 11 NuCMe](NHEt 3 ) [1](NHEt 3 ) and [B 12 H 11 NuCEt] (NHEt 3 ) [2](NHEt 3 ) in good yields.…”

“…33) have been reported and their reactivity has been investigated. 25,[33][34][35] In 2021, the first synthesis of the acetonitrilium and propionitrilium derivatives of the closo-dodecaborate anion was described, 36 and somewhat later the only example of nucleophilic addition to the highly activated triple bond B-N + uCCH 3 was reported. 37 In this contribution, we report the improved synthesis of the acetonitrilium and propionitrilium derivatives of the closo-dodecaborate dianion and unleash their potential in the addition reactions of water, alcohols, and secondary amines.…”

New Method for Synthesis of Substituted N-Borylated Dipeptides Based on Acetonitrile Derivative of the closo-Dodecaborate Anion

“…In the 11 B NMR spectra of the obtained derivative, a signal from the boron atom bound to the nitrogen atom of the nitrile substituent is observed in the region of -7.8 ppm [B(1), I = 1] and a complex signal from unsubstituted boron atoms are observed at -16.5 ppm [B (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12), I = 11, J B-H = 128 Hz]. In the 1 H NMR spectrum of compound 2, the fragment of the nitrile substituent is represented by signals at 6.56 ppm assigned to the hydrogen atom bonded to the nitrogen atom, and at 1.57 ppm assigned to the methyl group located in a stronger field compared to similar conjugates of the closo-decaborate anion [31]. The amino acid fragment is represented by the signals of protons bound to nitrogen atoms at 8.25 ppm, with hydrogen atoms of the benzene ring in the range 7.38-7.25 ppm, signals of protons bound to the α-carbon atom at 4.36 ppm, protons of the methyl group at 3.78 ppm, and two complex signals of nonequivalent protons of the methylene group at 3.27 and 2.93 ppm.…”

“…The development of methods for the preparation of nitrile derivatives of the closo-dodecaborate anion [30,31] will expand the possibilities for the creation of new promising preparations for 10 B-NCT on their basis.…”

Physiologically Active Compounds Based on Membranotropic Cage Carriers–Derivatives of Adamantane and Polyhedral Boron Clusters (Review)

“…The active study of new methods for the introduction of functional groups into boron cluster anions expands the possibilities for the design of new compounds, including those with physiologically active properties [ 92 , 93 ].…”