Steric control of the in/out sense of bridgehead substituents in macrobicyclic compounds: isolation of new "crossed chain" variants of in/out isomers

Michael Stollenz; Deeb Taher; Nattamai Bhuvanesh; Joseph H Reibenspies; Zuzana Baranová; John A Gladysz

doi:10.1039/c5cc05620a

Steric control of the in/out sense of bridgehead substituents in macrobicyclic compounds: isolation of new "crossed chain" variants of in/out isomers

Chem Commun (Camb). 2015 Nov 18;51(89):16053-6. doi: 10.1039/c5cc05620a.

Authors

Michael Stollenz¹, Deeb Taher¹, Nattamai Bhuvanesh¹, Joseph H Reibenspies¹, Zuzana Baranová¹, John A Gladysz¹

Affiliation

¹ Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA. Gladysz@mail.chem.tamu.edu.

PMID: 26345176
DOI: 10.1039/c5cc05620a

Abstract

Isomers of the cage like dibridgehead diphosphine P((CH2)14)3P (1) are treated with Ph3PAu(2,6-C6H3(Trip)2) (2 equiv.; Trip = 2,4,6-C6H2(iPr)3). With out,out-1, workup gives out,out-1·(Au(2,6-C6H3(Trip)2))2 (46%), as confirmed by a crystal structure. With in,out-1, crystallization affords not in,out-1·(Au(2,6-C6H3(Trip)2))2, but rather an out,out isomer in which one of the (CH2)14 segments threads through the macrocycle formed by the other two. Implications for mechanisms of interconversion of in,out isomers are analyzed.