Boranes, metalla

It is possible only to touch on heavier Group 14 organics in other actively developing fields such as metalla(car)boranes or in transition metal chemistry. 

BORONCOMPOUNDS - BORON HYDRIDES, HETEROBORANES AND THEIR METALLA DERIVATIVES] (Vol 4) Borane-drmethyl sulfide [13292-87-0]... 

From the discussion in Section II,C it should be clear that there is a relationship between the structures of borides and boranes as far as the boron networks are concerned. A comparison of the literature shows that the known structural diversity of the boranes is much greater than that of the borides. This may well be due to the rigorous conditions required for boride preparation that is, only the most stable boron networks are formed. TTie low-temperature routes illustrated in the foregoing work suggest an approach to presently unknown compounds with novel boride networks. Hence, the multitude of known metalla-boranes constitute a stockpile of potential precursors to metal borides with new and perhaps useful properties. 

For further details, see C.E. Housecroft (1994) Boranes and Metalla-boranes Structure, Bonding and Reactivity, 2nd edn, Ellis Horwood, (Iz. /J Hemel Hempstead, Chapter 3, and references cited therein. 

Both dimethylphenylphosphine-borane (107) and -sulfide (108) are enantio-selectively deprotonated by a lithiumalkyl (—)-sparteine complex as demonstrated by subsequent reaction with electrophiles to give products with e.e. values of 80-87% (Scheme 8). Oxidative coupling of (109) in the presence of copper(II) pivalate gives the (S. S)-isomer (110) as the major product. Asymmetric metalla-tion and silylation of diphenylphosphinyl ferrocene (111) using the chiral lithium amide base derived from di(l-methylbenzyl)amine has been reported to give an... 

The development of metallaborane chemistry in recent years has led to the discovery of some metallaborane structures containing the so-called isocloso deltahedra, which have a transition metal atom (e.g., Ru, Rh, Ir) located at a degree 6 vertex. Such isocloso metalla-borane dehahedra, except for the 11-vertex structures, are topologically different from the closo borane deltahedra foimd in the simple boranes and the... 

The organisation of this Report is similar to that of Volume 13. Cyclopentadienyl and arene complexes that contain metal-metal bonds, carbene, carbyne, or hydrocarbyl ligands, and reactions that involve replacement or elaboration of other ligands present, generally are not included (see Chapters 9-13). Only those metalla-borane and -carbaborane complexes that also incorporate a Cp or arene ligand are described, and crystal-structure determinations are included only where results of particular significance or solutions to structural problems are provided. 

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