Topics in Current Chemistry (2020) 378:1
1 3
In(OTf) 3 . High ee values and moderate drs were obtained using benzylic and benzhydrylic alcohols bearing strong donating aryl substituents. The presence of the
para-dimethylamino aryl group was essential and we can take advantage of its presence in further chemical transformations. Indium is not the only Lewis acid that
can be employed in S N 1-type reactions. As a matter of fact, a cooperative system
involving a diarylprolinol silyl ether with CuCl or IrCl 3 as active Lewis acids, has
been found to be active in the highly enantioselective intermolecular α-alkylation
of aldehydes with alcohols [88]. A wide variety of aldehydes and alcohols were
used for the alkylation of functionalized aldehydes affording the desired products
in high yields, excellent enantioselectivities, and good diastereoselectivities at room
temperature. Regarding the activation mode depicted as IV, Rueping has described
Scheme 12 Stereoselective propargylation with MacMillan catalyst in the presence of catalytic amount
of In(OTf) 3
Scheme 13 Indium(III) promoted organocatalytic enantioselective α-alkylation of aldehydes
Reprinted from the journal
46
1 3
In(OTf) 3 . High ee values and moderate drs were obtained using benzylic and benzhydrylic alcohols bearing strong donating aryl substituents. The presence of the
para-dimethylamino aryl group was essential and we can take advantage of its presence in further chemical transformations. Indium is not the only Lewis acid that
can be employed in S N 1-type reactions. As a matter of fact, a cooperative system
involving a diarylprolinol silyl ether with CuCl or IrCl 3 as active Lewis acids, has
been found to be active in the highly enantioselective intermolecular α-alkylation
of aldehydes with alcohols [88]. A wide variety of aldehydes and alcohols were
used for the alkylation of functionalized aldehydes affording the desired products
in high yields, excellent enantioselectivities, and good diastereoselectivities at room
temperature. Regarding the activation mode depicted as IV, Rueping has described
Scheme 12 Stereoselective propargylation with MacMillan catalyst in the presence of catalytic amount
of In(OTf) 3
Scheme 13 Indium(III) promoted organocatalytic enantioselective α-alkylation of aldehydes
Reprinted from the journal
46