Well-defined calcium and ytterbium complexes [{2-NC­(Ph)­NArC6H4CHNAr}­M­{N­(SiMe3)2}­(THF)] (M = Ca, Yb; Ar = 2,6-iPr2C6H3) have been synthesized and characterized. They catalyze the intermolecular hydrophosphination of alkenes, dienes, and alkynes with high activity and selectivity under mild conditions. Highly selective 1,4-additions (94–100%) for the conjugated dienes examined have been observed with both catalysts. The calcium complex exclusively catalyzes anti addition to alkynes, including terminal alkynes, while the ytterbium, in most cases, catalyzes syn addition. The calcium catalyst could promote hydrophosphination of hindered alkenes such as stilbene under relatively mild conditions.

Stable compounds with a boron-chalcogen (S or Se) valence double bond have been prepared via sequences involving insertion of the chalcogen into a B-H bond and subsequent hydrogen migration. X-ray diffraction studies and density functional theory calculations on the resulting compounds provide convincing evidence for the boron-chalcogen multiple bonding.

Monomeric iminoalane: A donor‐stabilized monomeric iminoalane was prepared by the reaction of 1 with an N‐heterocyclic carbene (see scheme). The X‐ray structure exhibits a very short AlN bond of 1.705(4) Å, which suggests multiple‐bond character. Treatment of the iminoalane with phenyl acetylene, aniline, and carbon monoxide resulted in addition reactions to the formal AlN bond, thus indicating that the AlN multiple bond is highly reactive.

Top cat: [(NHC)Yb{N(SiMe(3))(2)}(2)] adducts (NHC = N-heterocyclic carbene) are efficient catalysts for catalytic cross-dehydrogenative coupling of silanes with a range of primary and secondary amines to yield silylamines in high yields (82-100%) under mild reaction conditions. The catalytic activity and selectivity of the rare-earth-metal silylamides are modulated by altering the steric bulk of the NHC.

Have it BOth ways: Metal‐free anionic oxoboranes and Lewis acid stabilized oxoboranes that feature a formal BO double bond can be conveniently obtained from an N‐heterocyclic borinic acid in the presences of N‐heterocyclic carbenes (NHCs) and Lewis acids, respectively (see picture).