Unprecedented metalated phosphonite boranes were prepared from PH-substituted precursors and silyl amides. Althoughp otassium derivatives were thermally stable and could even be isolated and structurally characterised,l ithiated analogues proved to be unstable towards self-condensation under cleavage of LiOR at ambient temperature. Reaction studies revealed that the metalated phosphonite boranes exhibit ambiphilic character. Their synthetic potential as nucleophilic building blocks was demonstrated in the synthesis of the first stannylated phosphonite representing an ew structural motif in phosphine chemistry.

A linear solution‐phase synthesis of branched oligonucleotides with adamantane as core has been developed. The method uses conventional phosphoramidites only, achieves chain assembly without chromatography of intermediates, and overcomes the low reactivity of adamantane‐1,3,5,7‐tetraol as core. The assembly of four‐arm hybrids with up to 32 nucleotides total was performed, with monodisperse products of up to 10 kDa in size. Overall yields of 20 % over 19 steps (hexamer arms) and 11 % over 25 steps (octamer arms) of HPLC‐purified compounds were obtained. The adamantane‐based hybrids show more DNA‐dominated assembly properties than their analogues with larger lipophilic cores. Reversible formation of macroscopic amounts of materials through hybridization was achieved, both for self‐complementary systems and two‐hybrid systems with two non‐self‐complementary DNA sequences.

Cationic imidazolio-phosphines show two-sided reactivity towards bases, undergoing either Brønsted-type proton transfer to imidazolio-phosphides or autocatalytic Lewis acid/base reaction cascades to yield P-free imidazolium ions and oligophosphines.

The reversible reaction of H2 with a bis-phosphenium complex of chromium provides a rare example of 3d transition metal/phosphenium cooperativity. Photolysis induces the activation of H2 and yields a spectroscopically...

The Front Cover shows the starting materials of a solution‐phase synthesis of branched oligonucleotides and a series of reaction vessels of increasing size, illustrating the fact that there is a new, efficient, and scalable DNA synthesis that provides macroscopic amounts of branched DNA. While traditional solid‐phase synthesis of DNA is expensive to scale up, the new method readily produces hundreds of milligrams of branched oligonucleotides in a cost‐efficient manner using conventional laboratory equipment. This is important for producing DNA‐based materials in macroscopic quantities. More information can be found in the https://doi.org/10.1002/ejoc.201700686