Reaction of 4-CN-PhOH with [ClP(μ-N(t)Bu)]2 (1) (2:1 ratio) in the presence of Et3N produced the functionalized cyclodiphosph(III/III)azane [(4-CN-PhO)P(μ-N(t)Bu)]2 (2). Oxidation of 2 produced cyclodiphosph(V/V)azanes [(4-CN-PhO)(E)P(μ-N(t)Bu)]2 [E = O (3), S (4), and Se (5)]. This is the first example of a series of cyclodiphosph(V/V)azane derivatives obtained from a single cyclophosph(III/III)azane precursor where all the accessible chalcogen oxidized products are air-stable over prolonged periods of time.

Herein, we report a new application of the prize-winning Grubbs catalysts, which have been widely applied for olefin metathesis, for hydrogen production from aqueous-phase methanol reforming under easily achievable conditions (1 atm, <100 °C) with negligible CO formation. Out of the catalysts tested, the best turnover frequency (158 h–1) and turnover number (11424, 72 h) were both achieved with a third-generation Grubbs catalyst (G-III). The best TOF was achieved with G-III and is competitive when compared with some of the best results reported (Chem. Rev.2018118372433). Also, G-III is found to be a versatile catalyst for the dehydrogenation of ethanol and formic acid. Mechanistic studies and DFT calculations shed light on the reaction mechanism, which involves an unusual substrate (solvent)-assisted six-membered-ring (σ-bond) metathesis pathway. This work should open up new opportunities in catalyst design in connection with the hydrogen economy and, more generally, with the development of clean and renewable energies.

Dimeric cyclophosphazanes [{P(μ-NR)}2(μ-NR)]2 [R = (t)Bu ( 1) and iPr ( 3)] were oxidized with elemental selenium. During these reactions an unexpected C–N bond cleavage and N–H bond formation occurred. Compound 1 produced P4(μ-N(t)Bu)3(μ-NH)3Se4 ( 2) where three tBu groups were lost in the form of isobutylene. In contrast, during the oxidation of the less sterically hindered 3, the resulting product, P4(μ-N(i)Pr)5(μ-NH)Se4 ( 4), showed only one substituent loss. Theoretical studies confirmed the steric nature of the driving force underlying the different outcomes.

The first asymmetric total synthesis of the highly strained compound cerorubenic acid-III is reported. A type II intramolecular [5 + 2] cycloaddition allowed efficient and diastereoselective construction of the synthetically challenging bicyclo[4.4.1] ring system with a strained bridgehead (anti-Bredt) double bond in the final product. A unique transannular cyclization installed the vinylcyclopropane moiety with retention of the desired stereochemistry.