Boron-nitrogen heteroarenes hold great promise for practical application in many areas of chemistry. Enduring interest in realizing this potential has in turn driven perennial innovation with respect to these compounds' synthesis. This Perspective discusses in detail the most recent advances in methods pertaining to the preparation of BN-isosteres of benzene, naphthalene, and their derivatives. Additional focus is placed on the progress enabled by these syntheses toward functional utility of such BN-heterocycles in biochemistry and pharmacology, materials science, and transition-metal-based catalysis. The prospects for future research efforts in these and related fields are also assessed.

The photochemistry of 1,2-dihydro-1,2-azaborinine derivatives was studied under matrix isolation conditions and in solution. Photoisomerization occurs exclusively to the Dewar valence isomers upon irradiation with UV light (>280 nm) with high quantum yield (46 %). Further photolysis with UV light (254 nm) results in the formation of cyclobutadiene and an iminoborane derivative. The thermal electrocyclic ring-opening reaction of the Dewar valence isomer back to the 1,2-dihydro-1-tert-butyldimethylsilyl-2-mesityl-1,2-azaborinine has an activation barrier of (27.0±1.2) kcal mol . In the presence of the Wilkinson catalyst, the ring opening occurs rapidly and exothermically (ΔH=(-48±1) kcal mol ) at room temperature.

In the past few decades, homogeneous catalysis of arene and heteroarene reduction has grown into a mature research field. In particular, hydrogenation of heteroaromatic systems facilitates rapid access to many classes of fine chemicals and pharmaceutically relevant compounds. In this review, we discuss the advancements made in the field of homogeneous metal-catalyzed arene and heteroarene hydrogenation from its early beginnings to the present day. We also review homogeneous catalysts for the reverse dehydrogenation of cyclic saturated species back to their aromatic counterparts, as well as single-catalyst systems capable of performing reversible hydrogenationdehydrogenation reactions.

We provide a seminal example of the utility of the 1,2‐azaborine motif as a 4C+1N+1B synthon in organic synthesis. Specifically, conditions for the practically scalable photoisomerization of 1,2‐azaborine in a flow reactor are reported that furnish aminoborylated cyclobutane derivatives. The C−B bonds could also be functionalized to furnish a diverse set of highly substituted cyclobutanes.

Growing demand for sustainable chemical syntheses casts mechanochemistry in a new light as an environmentally benign alternative to traditional solvent-based methods. Given recent interest in Au(I) complexes for catalytic, materials,...

Glycerol is an ideal building block for the synthesis of complex molecules, because it is inexpensive and highly functionalized. We report the desymmetrization of glycerol through silyl transfer, using a chiral organic catalyst in high yield and enantioselectivity.

The photochemistry of 1,2‐dihydro‐1,2‐azaborinine derivatives was studied under matrix isolation conditions and in solution. Photoisomerization occurs exclusively to the Dewar valence isomers upon irradiation with UV light (>280 nm) with high quantum yield (46 %). Further photolysis with UV light (254 nm) results in the formation of cyclobutadiene and an iminoborane derivative. The thermal electrocyclic ring‐opening reaction of the Dewar valence isomer back to the 1,2‐dihydro‐1‐tert‐butyldimethylsilyl‐2‐mesityl‐1,2‐azaborinine has an activation barrier of (27.0±1.2) kcal mol−1. In the presence of the Wilkinson catalyst, the ring opening occurs rapidly and exothermically (ΔH=(−48±1) kcal mol−1) at room temperature.

Complete −CH 2 CH 2 − dehydrogenation of 1,2-dimethyl-1,2-BN-cyclohexene (1) was achieved using a Pd/C catalyst in a gas-phase microreactor. Arrhenius analysis yielded an activation energy (E a ) of 10.3 ± 0.3 kcal mol −1 and a pre-exponential factor (A) of 2.2 ± 0.2 (log A), respectively. These terms reflect a lesser kinetic favorability in comparison to those determined for all-carbon dimethylcyclohexene (E a = 8.6 ± 0.3 kcal mol −1 , log A = 3.6 ± 0.1). Despite being isostructural and isoelectronic with a CC bond, the B−N bond of 1 thus appears to confer a different measure of activity with respect to Pd-catalyzed −CH 2 CH 2 − dehydrogenation.Communication pubs.acs.org/Organometallics