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We report the facile activation of aryl E-H (ArEH; E = N, O, S; Ar = Ph or C6F5) or ammonia N-H bonds via coordination-induced bond weakening to a redox-active boron center in the complex, (1-). Substantial decreases in E-H bond dissociation free energies (BDFEs) are observed upon substrate coordination, enabling subsequent facile proton-coupled electron transfer (PCET). A drop of >50 kcal mol-1 in H2N-H BDFE upon coordination was experimentally determined.

We report here a new route for the preparation of [1,1′‐bis(o‐carboranyl)]borane, a 3D analogue of 9‐borafluorene, η2‐σ‐silane adduct (1‐H‐SiEt3) in high yields (>80 %). The nature of B−H−Si bonding was studied by density functional theory (DFT) computations. Preliminary reactivity study of 1‐H‐SiEt3 with small molecules was carried out. Interestingly, 1‐H‐SiEt3 reacts with benzophenone in hexane producing the deoxygenation product Ph2CH2. While in benzene, 1‐H‐SiEt3 reacts with benzophenone leading to mixture of Ph2CH2 and Ph3CH (3 : 1). Ph3CH is formed via addition of benzene to the carbonyl followed by deoxygenation. In contrast, the reaction of benzophenone with Et3SiH in presence of a catalytic amount of 1‐H‐SiEt3 leads to hydrosilylation product Ph2(H)C−OSiEt3. [ABSTRACT FROM AUTHOR]

In this work the first examples of C–N bond activation by insertion into a geometrically constrained PIII-centre are shown. The mechanisms of these activation processes leading to new PV species were studied both experimentally and computationally. Interestingly, in the case of insertion of the PIII-centre into an N–C(O)H bond, an unstable phosphoranyl-formaldehyde intermediate is probably formed, which undergoes decarbonylation in the presence of a catalytic amount of HCl producing a hydrophosphorane. [ABSTRACT FROM AUTHOR]

An air‐stable dicationic Zn2+ complex (1) in a tripod‐type ligand with non‐bound phosphorus base and three pyridinyl "arms" (TPPh) was synthesized. Remarkably, while 2 mol% of 1 at room temperature selectively catalyzed dehydrogenative borylation of terminal alkynes with HBPin, a lower loading of 1 (0.5 mol%) at 90 °C selectively promoted hydroboration reaction of the same alkynes skipping the dehydrogenative borylation step. The mode of action of 1 was proposed based on experimental observations as well as the mechanism of dehydrogenative borylation was studied by DFT computations. [ABSTRACT FROM AUTHOR]

We have demonstrated stepwise functionalization of chlorophosph(III)azane, [ClP(μ-NtBu)]2 with organic azides and chalcogens (S and Se). The in situ 31P{¹H} NMR spectroscopic investigations reveal that conversion of the basic PIII2N2 framework, leading to PV 2N2 proceeds via (PIII/PV)N2 intermediates. Under controlled conditions, the (PIII/PV)N2 intermediate species can be isolated, providing details of the reaction pathway and distribution of the cis and trans isomers of the PV2N2 products. It has also been demonstrated that neat reactions at elevated temperatures expedite the formation of PV2N2 products, without significantly affecting the yields and relative distribution of the cis and trans isomers. All new compounds reported here are potential building blocks for the assembly of inorganic macrocycles and polymers. [ABSTRACT FROM AUTHOR]

Reduction of the cyclodiphosphazane [(S=)ClP(μ-N tBu)]2 ( 1) with sodium metal in refluxing toluene proceeds via two different pathways. One is a Wurtz-type pathway involving elimination of NaCl from 1 followed by head-to-tail cyclization to give the hexameric macrocycle [(μ-S)P(μ-N tBu)2P(=S)]6 ( 2). The other pathway involves reduction of the P=S bonds of 1 to generate colorless singlet biradicaloid dianion trans-[S−P(Cl)(μ-N tBu)]22−, which is observed in the polymeric structures of three-dimensional [{(S−)ClP(μ-N tBu)2PCl(S)}Na(Na ⋅THF2)] n ( 3) and two dimensional [{(S−)ClP(μ-N tBu)2PCl(S)} (Na ⋅THF)2] n ( 4). [ABSTRACT FROM AUTHOR]

A sulfur ‐ bridged inorganic macrocycle and a room temperature singlet biradicaloid dianion have been isolated in the Wurtz reduction of a mixture of cis ‐ and trans ‐ dichlorophosph(V)azane. It appears that these products from the same reaction are the outcome of two different reduction pathways. This approach may facilitate the discovery of new types of inorganic macrocycles and new polymeric assemblies similar to those observed in this work. More information can be found in the Full Paper by S. Singh, D. S. Wright et al. on page 12027 ff. [ABSTRACT FROM AUTHOR]

In this work the first examples of C-N bond activation by insertion into a geometrically constrained P III -centre are shown. The mechanisms of these activation processes leading to new P V species were studied both experimentally and computationally. Interestingly, in the case of insertion of the P III -centre into an N-C(O)H bond, an unstable phosphoranyl-formaldehyde intermediate is probably formed, which undergoes decarbonylation in the presence of a catalytic amount of HCl producing a hydrophosphorane.

A geometrically constrained phosphenium cation in bis(pyrrolyl)pyridine based NNN pincer type ligand (1 + ) was synthesized, isolated and its preliminary reactivity was studied with small molecules. 1 + reacts with MeOH and Et 2 NH, activating the O-H and N-H bonds via a P-center/ligand assisted path. The reaction of 1 + with one equiv. of H 3 NBH 3 leads to its dehydrogenation producing 5. Interestingly, reaction of 1 + with an excess H 3 NBH 3 leads to phosphinidene (P I ) species coordinating to two BH 3 molecules (6). In contrast, [1 + ][OTf] reacts with Et 3 SiH by hydride abstraction yielding 1-H and Et 3 SiOTf, while [1 + ][B(C 6 F 5 ) 4 ] reacts with Et 3 SiH via an oxidative addition type reaction of Si-H bond to P-center, affording a new P V compound (8). However, 8 is not stable over time and degrades to a complex mixture of compounds in matter of minutes. Despite this, the ability of [1 + ][B(C 6 F 5 ) 4 ] to activate Si-H bond could still be tested in catalytic hydrosilylation of benzaldehyde, where 1 + closely mimics transition metal behaviour., (© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Reduction of the cyclodiphosphazane [(S=)ClP(μ-NtBu)]2 (1) with sodium metal in refluxing toluene proceeds via two different pathways. One is a Wurtz-type pathway involving elimination of NaCl from 1 followed by head-to-tail cyclization to give the hexameric macrocycle [(μ-S)P(μ-NtBu)2 P(=S)]6 (2). The other pathway involves reduction of the P=S bonds of 1 to generate colorless singlet biradicaloid dianion trans-[S-P(Cl)(μ-NtBu)]2 (2-) , which is observed in the polymeric structures of three-dimensional [{(S-)ClP(μ-NtBu)2 PCl(S)}Na(Na⋅THF2 )]n (3) and two dimensional [{(S-)ClP(μ-NtBu)2 PCl(S)} (Na⋅THF)2 ]n (4)., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)