A Facile, Palladium‐Catalyzed Synthesis of 1,1′‐Bi(bicyclo[1.1.1]pentanes)

Symmetrically 3,3′-disubstituted 1,1′-bi(bicyclo[1.1.1]pentanes) were synthesized in a four-step procedure, using commercially available starting materials, in fair overall yields (51−60%). In this synthesis the final step is an unexpected bridgehead-to-bridgehead homocoupling of bicyclo[1.1.1]pent-1-ylmagnesium halide catalyzed by palladium(II). Only 1.1 mol percent of bis(acetonitrile)palladium(II) chloride and two equivalents of bromomethane were necessary to accomplish this reaction. The bromomethane is essential to convert Pd0 into PdII. The X-ray structure of the [2]staffane 1c has been determined and shows a nonbonded C1−C3 distance of 1.907 A in the bicyclo[1.1.1]pentyl subunit.

[1]  B. Ziemer,et al.  A Facile Route to Bridgehead Disubstituted Bicyclo[1.1.1]pentanes Involving Palladium‐Catalyzed Cross‐Coupling Reactions , 1999 .

[2]  J. Michl,et al.  Symmetric Bridgehead-to-Bridgehead Coupling of Bicyclo[1.1.1]pentanes and [n]Staffanes , 1998 .

[3]  W. Dailey,et al.  1.1.1PROPELLANE : (TRICYCLO1.1.1.01 3PENTANE) , 1998 .

[4]  Y. Obeng,et al.  Self-Assembled Monolayers of Parent and Derivatized [n]Staffane-3,3(n-1)-dithiols on Polycrystalline Gold Electrodes , 1992 .

[5]  Josef Michl,et al.  Toward a molecular-size tinkertoy construction set. Preparation of terminally functionalized [n]staffanes from [1.1.1]propellane , 1992 .

[6]  Günter Szeimies,et al.  Verkürzte CC-Bindungen in gekuppelten Bicyclo[1.1.0]butanen† , 1989 .

[7]  U. Bunz,et al.  Concerning the Synthesis of [1.1.1]Propellane , 1989 .

[8]  K. Polborn,et al.  Gekoppelte Polycyclen: Synthese, Struktur und Isomerisierung von 1,1′-Bihomocuban , 1988 .

[9]  K. Polborn,et al.  Brückenkopf-gekoppelte Bicyclo[1.1.1]pentane: Synthese und Struktur , 1988 .

[10]  J. Belzner,et al.  Tetracyclo[5.1.0.01,6.02,7]octane, a [1.1.1]propellane derivative, and a new route to the parent hydrocarbon , 1985 .

[11]  D. Milstein,et al.  Mechanism of reductive elimination. Reaction of alkylpalladium(II) complexes with tetraorganotin, organolithium, and Grignard reagents. Evidence for palladium(IV) intermediacy , 1979 .

[12]  R. Puddephatt,et al.  Methyl for halogen exchange reactions between palladium(II), platinum(II), gold(I), and gold(III) complexes , 1975 .

[13]  R. Puddephatt,et al.  Retention of stereochemistry at both platinum centres in the symmetrisation reaction between cis-[PtMe2(PMe2Ph)2] and cis-[Pt(NO3)2(PMe2Ph)2] , 1975 .

[14]  J. Kraut,et al.  Mechanism of single-bond shortening. Evidence from the crystal structures of 1-biapocamphane, 1-binorbornane, and 1-biadamantane , 1968 .