1,3-Diamines not only are significant motifs in natural products, but also serve as building blocks in synthetic organic chemistry. However, unlike their 1,2-diamine counterparts, limited efforts have been devoted to the development of an effective synthetic approach to 1,3-diamines. In this review, the synthetic methods for the preparation of 1,3-diamines are summarized.
As afundamental type of carbonylation reaction, the alkoxy-and hydroxy-carbonylation of unsaturated hydrocarbons constitutes one of the most important industrial applications of homogeneous catalysis.H owever,o wingt o the difficulties in controlling multi-selectivities for asymmetric hydrocarbonylation of alkenes,this reaction is typically limited to vinylarenes and analogues.I nt his work, ah ighly efficient asymmetric alkoxy-and hydroxy-carbonylation of b-carbonyl functionalizedalkenes was developed, providing practical and easy access to various densely functionalized chiral molecules with high optical purity from broadly available alkenes,C O, and nucleophiles (> 90 examples,8 4-99 %e e). This protocol features mild reaction conditions and abroad substrate scope, and the products can be readily transformed into ad iverse arrayo fc hiral heterocycles.C ontrol experiments revealed the key role of the b-carbonyl group in determining the enantioselectivity and promoting the activity,w hich facilitates chiral induction by coordination to the transition metal as rationalized by DFT calculations.T he strategy of utilizing an innate functional group as the directing group on the alkene substrate might find further applications in catalytic asymmetric hydrocarbonylation reactions.
α,β-Unsaturated primary amides have found numerous applications in drug development, organic materials, and polymer sciences. However, the catalytic synthesis of α,β-unsaturated primary amides via carbonylation of alkynes has long been an elusive endeavor. Here, we report a novel palladium-catalyzed hydroaminocarbonylation of alkynes with NHCl as the amine source, enabling the highly chemo- and regioselective synthesis of α,β-unsaturated primary amides. A variety of alkynes, including aromatic alkynes, aliphatic alkynes, terminal alkynes, internal alkynes, as well as diynes with various functional groups, react well. The method turns the parasitic noncoordination ability of ammonium salts into a strategic advantage, enabling the gram-scale reaction to be performed in the presence of 0.05 mol % of catalyst with excellent selectivity.
A Pd-catalyzed asymmetric double hydroxycarbonylation of terminal alkynes was developed by using relay catalysis, providing a highly efficient route to chiral succinic acids (41 examples, 76-94 %, 94-99 % ee). Key to success was the combinatorial use of a Pd precursor with two distinct phosphine ligands in one pot. The synthetic utilities of this protocol were showcased in the facile synthesis of key intermediates for chiral pharmaceuticals.
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