Catalytic Enantioselective Decarboxylative Cyanoalkylation of Imines by Using Palladium Pincer Complexes with<i>C</i><sub>2</sub>-Symmetric Chiral Bis(imidazoline)s
Manifold products: The enantioselective decarboxylative Mannich‐type reaction of cyanoacetic acid with N‐ (2‐pyridinesulfonyl)imines catalyzed by chiral 1,3‐bis(imidazolin‐2‐yl)benzene (Phebim)–PdII complexes afforded products with good enantioselectivity (see scheme). The reaction was applied to a wide range of imines with good yield and enantioselectivity. The obtained products can be converted into
An asymmetric organocatalytic vinylogous Mannich reaction of 3-methyl-5-arylfuran-2(3<i>H</i>)-ones with <i>N</i>-(2-pyridinesulfonyl) imines: enantioselective synthesis of δ-amino γ,γ-disubstituted butenolides
An asymmetricorganocatalytic vinylogous Mannichreaction of 3-methyl-5-arylfuran-2(3H)-ones with N-(2-pyridinesulfonyl)imines has been developed with 5 mol% thiourea–tertiary amine as the catalyst. A series of δ-amino γ,γ-disubstituted butenolides bearing adjacent quaternary and tertiary stereocenters are efficiently obtained with satisfactory results (up to 90% yield, 90 : 10 dr, and 95 : 5 er).
Enantioselective C--C bond formation to 2-pyridinesulfonylimines afforded products with good enantioselectivity. Dynamic induction of chirality on the sulfur by coordination of a chiral Lewis acid to the pyridine nitrogen and one of the prochiral sulfonyl oxygens induces enantioselectivity. Since the 2-pyridinesulfonyl group can easily be removed after the reaction, it acts not only as an activating
The catalyticenantioselectivereaction of diphenylmethylidene‐protected α‐aminoacetonitriles with imines has been developed. Good yields and diastereo‐ and enantioselectivities were observed for the reaction of various imines usingchiralbis(imidazoline)/Pd catalysts. The reaction of α‐aminonitriles with di‐tert‐butyl azodicarboxylate afforded chiral α,α‐diaminonitriles in high yields with high