ja4032727_si_003.cif (30.88 kB)
Gold-Catalyzed Cycloisomerization of 1,6-Diyne Carbonates and Esters to 2,4a-Dihydro‑1H‑fluorenes
dataset
posted on 2013-05-29, 00:00 authored by Weidong Rao, Ming Joo Koh, Dan Li, Hajime Hirao, Philip Wai Hong ChanA synthetic
method to prepare 2,4a-dihydro-1H-fluorenes
efficiently from gold(I)-catalyzed 1,2-acyloxy migration/cyclopropenation/Nazarov
cyclization of 1,6-diyne carbonates and esters is described. The suggested
reaction pathway provides rare examples of [2,3]-sigmatropic rearrangement
in this class of compounds as well as the involvement of an in situ
formed cyclopropene intermediate in gold catalysis. Experimental and
ONIOM(QM:QM′) [our own n-layered integrated
molecular orbital and molecular mechanics(quantum mechanics:quantum
mechanics′)] computational studies based on the proposed Au
carbenoid species provide insight into this unique selectivity.