The reaction of N,C,N‐chelated stibinidene ArSb (1) (Ar=C6H3‐2,6‐(CH=NtBu)2) with selected N‐alkyl/aryl‐maleimides RN(C(O)CH)2 (R=Me, tBu, Ph) gave the addition products with bridged bicyclic [2.2.1] structure containing an antimony atom at the bridgehead position, fused with a 6‐membered benzene and a 5‐membered N‐alkyl/aryl‐pyrrolidine ring. These compounds were completely characterized. More importantly, additional studies showed that these reactions are reversible in solution, thereby representing an unprecedented reversible activation of a C=C bond by an antimony(I) compound.

Reduction of C,N-chelated chloroborane [2-(CH=NtBu)C6H4]BPhCl () with the potassium metal afforded (3,3')-bis(1-Ph-2-tBu-1H-2,1-benzazaborole) (2). Compound 2 is formed via C-C reductive coupling reaction. Subsequent reduction of 2 with two equivalents of the potassium metal produced orange crystals of 1Ph-2tBu-1H-2,1-benzazaborolyl (Bab) potassium salt K(THF)(Bab) (3). Compound 3 is able to react with simple electrophiles (MeI or Me3SiCl) resulting in the formation of substituted 1H-2,1-benzazaboroles.

The reactivity of two N,C,N-chelated bismuthinidenes, that is, [2, 2 C 6 H 3 ]Bi (1) and its metastable analogue [2,6-(Me 2 NCH 2 ) 2 C 6 H 3 ]Bi (2), toward organic substrates containing C(sp 3 )−X bond (where X = I or OTf) is reported. The aim of this study is to prove the potential of the Bi(I) center in 1 and 2 to participate in an oxidative addition toward C−X bonds under formation of corresponding trivalent bismuth compounds. The influence of the substrate is examined; thus, simple primary alkyls (including fluorinated ones) as well as more branched substrates are considered to find the limits of these reactions and recognize the differences in the reactivity between 1 and 2. All products were characterized by means of high-resolution electrospray ionization mass spectrometry (ESI-MS); 1 H, 13 C, and 19 F NMR spectroscopy; and single-crystal X-ray diffraction analysis.

Two types of N,C,N-chelated pnictinidenes, i.e., [2-(RNHCH2)-6-(RN  CH)­C6H3]­E (1-E-R) and [2,6-(RNCH)2C6H3]­E (2-E-R, where E = As, Sb, Bi), are targeted in this study. 2-E-R could be obtained by simple reduction of respective precursors [2,6-(RNCH)2C6H3]­ECl2 (i.e., (2-E-R)­Cl2) with KC8 for E = As, Sb, or Bi with R being tBu, Ad, or Dipp. By contrast, the utilization of a bulky hydride, i.e., K-selectride, allowed the isolation of 1-E-R for E = As or Sb and R = Dipp, while the utilization of other pincer ligands, where R = tBu or Ad, led only to mixtures of both 1-E-R and 2-E-R. For bismuth, even the Dipp-substituted pincer ligand provided a mixture of 1-Bi-Dipp and 2-Bi-Dipp only. The structures and chemical properties of these sets of compounds, i.e., 1-E-Dipp, 2-E- t Bu, and 2-E-Dipp, were compared using X-ray diffraction analysis, UV–vis spectroscopy including an extensive theoretical study, and CV measurements. The oxidation of 2-E-Dipp (E = As, Sb, Bi) by air resulted only in the formation of complicated mixtures, while oxidation of 1-E-Dipp (E = As or Sb) cleanly produces (1′-E-Dipp)­OH as a result of a tautomeric NH → OH shift at elusive oxides (1-E-Dipp)­O under formation of a new E–N covalent bond. To examine the potential of such tautomerization-driven stabilization of oxidation products, the reactivity of 1-E-Dipp (E = As or Sb) toward other chalcogens is also reported, including a theoretical study.

The reaction of 2-(tBuNCH)C 6 H 4 TeCl with silver salts of weakly coordinating anions, AgX {X = O 3 SCF 3 , SbF 6 , or Al[OC(CF 3 ) 3 ] 4 }, provided the aryltellurenyl salts [2-(tBuNCH)-C 6 H 4 Te](O 3 SCF 3 ) (1), [2-(tBuNCH)C 6 H 4 Te](SbF 6 ) (2), and [2-(tBuNCH)C 6 H 4 Te]{Al[OC(CF 3 ) 3 ] 4 } (3), which comprise loosely associated ion pairs in the solid state. In solution, 1−3 undergo electrolytic dissociation into the tellurenyl cation [2-(tBuNCH)-C 6 H 4 Te] + ([4] + ) and the respective anions X − to various degrees, which was investigated by multinuclear NMR spectroscopy and conductivity measurements. The electronic structure of 1−3 and [4] + at both multiplicities (M = 1 and 3) was studied by DFT calculations using a set of real-space bond indicators. NICS calculations confirm the aromatic character of the central C 3 NTe ring in [4] + (M = 1). FIA calculations suggest that [4] + is a Lewis superacid.