Gold(I)-catalyzed enantioselective [3+2] and [3+3] cycloaddition reactions of propargyl acetals/ketals.
An asymmetric gold(I)-catalyzed [3+2] cycloaddition of propargyl acetals/ketals and aldehydes is reported, which proceeds via stepwise migration-fragmentation of acetals/ketals and cycloaddition of the in situ generated gold-carbenoid intermediate. Various functionalized 2, 5-dihydrofurans were obtained in good yields and high enantioselectivities. Furthermore, an example of the first gold(I) catalyzed [3+3] cycloaddition of secondary propargyl ketals and nitrones is presented.
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Cristina
C
Navarro
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Nathan D
ND
Shapiro
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Maurizio
M
Bernasconi
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Takahiro
T
Horibe
Department of Chemistry, University of California, Berkeley, California 94720, United States.
F Dean
FD
Toste
Cycloaddition; Enantioselective catalysis; Gold; Homogeneous catalysis; Propargyl acetals/ketals