The ability of PTA (PTA = 1,3,5-triaza-7-phosphaadamantane) and its N-benzylated derivative (N-Bz-PTA)Cl to interact with the randomly methylated beta-cyclodextrin (RAME-beta-CD) has been studied by UV-vis and NMR spectroscopies. Both ligands could be considered as non-interacting phosphines with respect to RAME-beta-CD. This has been turned to account in a rhodium-catalyzed hydroformylation reaction of 1-decene. A comparison with TPPTS (sodium salt of trisulfonated triphenylphosphine) highlights the beneficial effects of the PTA-based ligands on the chemoselectivity. Actually, chemoselectivities in aldehydes obtained with PTA and (N-Bz-PTA)Cl were very high (>98%) whatever the temperature. Moreover, contrary to what was observed with TPPTS, no decrease in regioselectivity was noticed as the linear to branched aldehydes ratio remains constant. (C) 2009 Elsevier B.V. All rights reserved.