Synthesis, structure, and reactivity of .eta.2-1,3-diene and enyne complexes of the chiral rhenium Lewis acid [(.eta.5-C5H5)Re(NO)(PPh3)]+: ozonolysis within a metal coordination sphere Academic Article uri icon

abstract

  • Reaction of [(η5-C5H5)Re(NO)(PPh3)(ClC6H5)]+BF4− (1) and trans-piperylene at room temperature (RT) gives [(η5-C5H5)Re(NO)(PPh3)(η2-H2CCHCHCHCH3)]+BF4− (2a; 72%) as a 63:37 mixture of RS,SR/RR,SS diastereomers. At 95 °C, (89–90):(ll–10) mixtures are obtained (84–88%). No linkage isomers with coordinated CHCHCH3 moieties are observed. Reaction of 1 and isoprene (RT) gives [(η5-C5H5)Re(NO)(PPh3)(H2CCHC(CH3)CH2)]+BF4− (90%) as a 65:15:7:13 mixture of isomers. At 95 °C, 95:2:1:2 mixtures are obtained (>99%). The major products have coordinated H2CCH moieties ((RS,SR)/(RR,SS)−2b); the minor products have coordinated C(CH3)CH2 moieties. Reactions of 1 or the corresponding dichloromethane complex and vinylacetylene (RT) give (7–17):(9–35):(61–44):(23–4) mixtures of the RS,SR and RR,SS diastereomers of alkene complex [(η5-C5H5)Re(NO)(PPh3)(η2-H2CCHCCH)]+BF4− and the sc and ac Re(C̤C) rotamers of alkyne complex [(η5-C5H5)Re(NO)PPh3)(H2CCH-η2-CCH)]+BF4−. Ozonolyses of 2a and 2b cleave the free CC moieties to give alkene complexes of acrolein and methyl vinyl ketone (79–73%). The crystal structure of (RS,SR)−2a. shows an s-trans diene conformation. Other structural features of the preceding compounds are analyzed. Rationales for the kinetic and thermodynamic binding selectivities are given. © 1993, American Chemical Society. All rights reserved.

author list (cited authors)

  • Peng, T. S., Wang, Y., Arif, A. M., & Gladysz, J. A.

citation count

  • 15

publication date

  • November 1993