Iterative protecting group-free cross-coupling leading to chiral multiply arylated structures

Iterative protecting group-free cross-coupling leading to chiral multiply arylated structures.

The Suzuki-Miyaura cross-coupling is one of the most often utilized reactions in the synthesis of pharmaceutical compounds and conjugated materials. In its most common form, the reaction joins two sp(2)-functionalized carbon atoms to make a biaryl or diene/polyene unit. These substructures are widely found in natural products and small molecules and thus the Suzuki-Miyaura cross-coupling has be...

Strategies for Protecting Group Free Glycosidation

Enhancing the usefulness of cross dehydrogenative coupling reactions with a removable protecting group.

A removable protecting group has been identified that allows the products of widely-used cross dehydrogenative couplings to be synthetically elaborated. The method can be used with enantiopure amines with no loss of enantiomeric excess. The methodology is exemplified by a new synthesis of enantiopure praziquantel, the drug used in the treatment of millions of people suffering from the neglected...

Metal-mediated coupling of amino acid esters with isocyanides leading to new chiral acyclic aminocarbene complexes.

Metal-mediated coupling between equimolar amounts of cis-[PdCl2(CNR1)2] (1–5) and the amino acid esters L-HTyrOMe (7) or L-HProOtBu (8) proceeds at 40 °C in chloroform over ca. 6 h. The subsequent workup affords the complexes cis-[PdCl2(CNR1){C(TyrOMe)vNHR1}] (R1 = Xyl 9, 2-Cl-6-Me-C6H3 10) or cis-[PdCl2(CNR1){C(ProOtBu)vNHR1}] (R1 = Xyl 11, 2-Cl-6-Me-C6H3 12, Cy 13, tBu 14, 2-naphthyl 15) in g...

Stepwise, Protecting Group Free Synthesis of [4]Rotaxanes.

Despite significant advances in the last three decades towards high yielding syntheses of rotaxanes, the preparation of systems constructed from more than two components remains a challenge. Herein we build upon our previous report of an active template copper-catalyzed azide-alkyne cycloaddition (CuAAC) rotaxane synthesis with a diyne in which, following the formation of the first mechanical b...