open access

https://hdl.handle.net/2115/17013

Synthesis and properties of SMAPs 1-phospha-4-silabicyclo[2.2.2]octane derivatives

英語

electrostatic potential minimum

2006-02-09

ARKAT USA, INC.

ARKIVOC

2006

359-369

Part (vii): Special Issue Plenary and Invited Lectures ICHC-20

Synthesis and properties of a new class of trialkylphosphine ligands SMAPs (1-phospha-4-silabicyclo[2.2.2]octane derivatives, named after silicon-constrained monodentate alkylphosphine) with Me3P-like steric demand around the phosphorus center are described. A new feature of this class of ligands is the presence of a site for functionalization at the backside of the P-lone pair, which is not the case for Me3P. The SMAP ligands contain phosphorus and silicon atoms at each bridgehead of the bicyclo[2.2.2]octane framework. The molecular constraint of the bicyclic framework makes the steric demand around the phosphorus center as small as that of Me3P and projects the P-lone pair and the Si-substituent (R) in diametrically opposite directions on the straight line defined by the two bridgehead atoms. SMAP derivatives bearing Si substituents with varied electronic natures are obtainable by transforming the parent compound 4-phenyl-phospha-4-silabicyclo[2.2.2]octane (Ph-SMAP) through Si–Ph bond cleavage, and they constitute a class of electronically tunable trialkylphosphines. DFT calculations indicated that the parent ligand Ph-SMAP is similar to Me3P in donor power and that the tunable range of the donor power overlaps those of (t-Bu)3P and RAr2P (R: alkyl, Ar: aryl).

学術雑誌論文

Version of Record

1424-6376