Lipase-Catalyzed Kinetic Resolution of <i>C</i>₁-Symmetric Heterocyclic Biaryls

Bismuth(III)-Catalyzed Oxidative Cross-Coupling of 3-Hydroxycarbazoles with Arenols under an Oxygen Atmosphere

“…34−36 efficient for biaryl synthesis, their toxicity can be a drawback. This problem can be overcome using heterogeneous catalysts; 35,36 however, certain limitations, such as metalcatalyst leaching, still remain. Sasai and Takizawa et al reported an electronic method to avoid the use of transition metals lately.…”

“…The oxidative cross-coupling (OCC) of two aromatic compounds is a powerful and useful tool for C–C bond formation and the synthesis of various C 1 -symmetric biaryls. − Particularly, the OCCs of carbazoles have attracted considerable attention because of the wide versatility of the products in the pharmaceutical and materials science fields. − Recently, several vanadium-catalyzed chemo- and regioselective OCCs of carbazoles were reported (Scheme A). − Although transition-metal catalysts are extremely efficient for biaryl synthesis, their toxicity can be a drawback. This problem can be overcome using heterogeneous catalysts; , however, certain limitations, such as metal-catalyst leaching, still remain. Sasai and Takizawa et al reported an electronic method to avoid the use of transition metals lately. , Organobismuth­(V) compounds can be used in stoichiometric arylation reactions (Scheme B).…”

Biocatalytic Atroposelective Synthesis of Axially Chiral N-Arylindoles via Dynamic Kinetic Resolution

“…Among the catalytic methodologies developed for the atroposelective synthesis of (hetero)­biaryls, biocatalysis has been scarcely applied in relative terms, but there is an increasing interest in the methodology . An overview of the state of the art reveals that hydrolytic enzymes (lipases) are the most common type of enzymes, often applied to kinetic resolution (KR), desymmetrization, and, more recently, to an elegant dynamic kinetic resolution (DKR) of BINOL derivatives, using a ruthenium complex as cocatalyst to facilitate the required racemization (Scheme A). Oxidative cross-coupling of phenol derivatives, which is the main biosynthetic route in nature for the atroposelective formation of axially chiral biaryls, is also a challenging target in the field of biocatalytic transformations.…”