Regioselective and enantioselective addition of thioacids to terminal allenes is reported employing a rhodium(i)/DIOP catalyst system. Complete catalyst control of diastereoselectivity was achieved upon addition of chiral amino thioacids to allenes.
Yndiamides, N,N-disubstituted alkynes, are versatile building blocks for the synthesis of nitrogen-containing organic molecules. Unlike ynamides, relatives that are inherently polarized by a single nitrogen substituent, their pseudo-symmetric nature renders regioselective reactions challenging. Here we report investigations into the regioselective addition of Brønsted acids to non-symmetric yndiamides, a reaction that delivers N,O,N- and N,S,N-trisubstituted ketene acetals with excellent regio- and stereoselectivity.
A
photocatalytic method for the alpha-selective hydroaminoalkylation of
cinnamate esters has been developed. The reaction involves the
regioselective addition of alpha-aminoalkyl radicals generated from
aniline derivatives or aliphatic amines to the alpha-position of
unsaturated esters. The scope of aromatic alkenes was extended to
styrenes undergoing hydroaminoalkylation with anti-Markovnikov
selectivity, which confirms the importance of the aromatic group at the
beta-position. Simple scale-up is demonstrated under continuous-flow
conditions, highlighting the practicality of the method.<br>
A
photocatalytic method for the alpha-selective hydroaminoalkylation of
cinnamate esters has been developed. The reaction involves the
regioselective addition of alpha-aminoalkyl radicals generated from
aniline derivatives or aliphatic amines to the alpha-position of
unsaturated esters. The scope of aromatic alkenes was extended to
styrenes undergoing hydroaminoalkylation with anti-Markovnikov
selectivity, which confirms the importance of the aromatic group at the
beta-position. Simple scale-up is demonstrated under continuous-flow
conditions, highlighting the practicality of the method.<br>
We describe a strategy for the enantio- and diastereoselective synthesis of homoallylic α-trifluoromethyl amines by the catalytic hydroalkylation of terminal dienes. Trifluoromethylsubstituted isatin-derived azadienolate nucleophiles undergo γ-selective alkylation with a Pd–DTBM-SEGPHOS catalyst, which additionally promotes regioselective addition to the diene and delivers products in up to 86% yield, 10:1 dr, and 97.5:2.5 er.
Rhodium-catalyzed regioselective addition of thioacids to terminal allenes: enantioselective access to branched allylic thioesters