TY  - JOUR
AB  - 1,2,3,4,5-Pentamethyl-1,3-cyclopentadien-5-carbonyl chloride (2) is formed in good yields by the reaction of pentamethylcyclopentadienyllithium (1) with phosgene. The corresponding carbothioyl chloride 3 is synthesized by treatment of 1 with thiophosgene. Both acyl chlorides are stable against air and moisture and difficult to attack in S(N)2-type reactions. Treatment of 2 and 3 with trimethyl(pentamethylcyclopentadienyl)stannane in the presence of boron trifluoride - ether leads to bis(1,2,3,4,5-pentamethyl-1,3-cyclopentadien-5-yl) ketone (S) and thioketone (6), respectively. Even at room temperature, S and 6 tend to intramolecular [4 + 2] cycloaddition reactions. X-ray crystal structure investigations of 2, 5, and 6 show the steric demand of the pentamethylcyclopentadienyl ligand and explain the untypical chemical behavior of 2 and the easy [2 + 4] cycloaddition reactions of 5 and 6.
DA  - 1993
DO  - 10.1002/cber.19931260219
KW  - 3
KW  - 2
KW  - 4
KW  - 3-CYCLOPENTADIENE-5-CARBOTHIOYL CHLORIDE
KW  - 1
KW  - 3-CYCLOPENTADIENE-5-CARBONYL CHLORIDE
KW  - PREFORMATION
KW  - DIELS-ALDER
KW  - 5-PENTAMETHYL-1
KW  - 3-CYCLOPENTADIEN-5-YL)
KW  - BIS(1
KW  - THIOKETONE
KW  - 3-CYCLOPENTADIEN
KW  - KETONE
LA  - ger
IS  - 2
M2  - 415
PY  - 1993
SN  - 0009-2940
SP  - 415-420
T2  - CHEMISCHE BERICHTE-RECUEIL
TI  - Bis(pentamethylcyclopentadienyl)keton und -thioketon: Kohlenstoff-Verbindungen mit präformierter Diels-Alder-Geometrie
UR  - https://nbn-resolving.org/urn:nbn:de:0070-bipr-4954
Y2  - 2024-11-22T02:17:47
ER  -