BINOL as a chiral element in mechanically interlocked molecules

Abstract

In this minireview we present the use of the axially chiral 1,1'-binaphthyl-2,2'-diol (BINOL) unit as a stereogenic element in mechanically interlocked molecules (MIMs). We describe the synthesis and properties of such BINOL-based chiral MIMs, together with their use in further diastereoselective modifications, their application in asymmetric catalysis, and their use in stereoselective chemosensing. Given the growing importance of mechanically interlocked molecules and the key advantages of the privileged chiral BINOL backbone, we believe that this research area will continue to grow and deliver many useful applications in the future.

One‐Pot Synthesis of Axially and Centrally Chiral A‐type Nanogrids

“…[ 21‐22 ] Of these, biaryl axially chiral molecules, particularly 2,2’‐disubstituted derivatives of 1,1’‐binaphthyl, are a versatile class of compounds that have found applications in many areas of chemistry and material. [ 23‐25 ] The robust configurational stability of binaphthyl derivatives in a broad range of conditions, [ 26 ] combined with their tunable chiral dihedral angle, makes them an ideal platform for transferring stereoinformation and exhibiting excellent optical properties. [ 27 ] Here, we propose a fascinating class of A‐type nanogrids (AGs), which consist of difluorenyl biaromatic derivatives (green and blue, A2 synthons which represent two reaction sites) and thiophene derivatives (red, B2 synthons which represent two reaction sites, Figure 1).…”

Ring‐to‐Thread Chirality Transfer in [2]Rotaxanes for the Synthesis of Enantioenriched Lactams

“…Whereas [2]rotaxanes containing chiral elements at the thread are more or less habitual in the literature,[ 3 , 5 ] those containing stereogenic elements at the ring have been scarcely reported. In most of these latter species, the stereogenic unit at the ring is a enantioenriched binaphtyl unit [27] which imposes a chiral environment useful for inducing a chiroptical response to an achiral thread, [28] for controlling the helical twisting of a polyacetylene macromolecule [29] and for achieving enantioselective transformations when used as catalysts. [ 30 , 31 ]…”

Ring‐to‐Thread Chirality Transfer in [2]Rotaxanes for the Synthesis of Enantioenriched Lactams

“…Whereas [2]rotaxanes containing chiral elements at the thread are more or less habitual in the literature, [3, 5] those containing stereogenic elements at the ring have been scarcely reported. In most of these latter species, the stereogenic unit at the ring is a enantioenriched binaphtyl unit [27] which imposes a chiral environment useful for inducing a chiroptical response to an achiral thread, [28] for controlling the helical twisting of a polyacetylene macromolecule [29] and for achieving enantioselective transformations when used as catalysts [30, 31] …”

“…Whereas [2]rotaxanes containing chiral elements at the thread are more or less habitual in the literature, [3,5] those containing stereogenic elements at the ring have been scarcely reported. In most of these latter species, the stereogenic unit at the ring is a enantioenriched binaphtyl unit [27] which imposes a chiral environment useful for inducing a chiroptical response to an achiral thread, [28] for controlling the helical twisting of a polyacetylene macromolecule [29] and for achieving enantioselective transformations when used as catalysts. [30,31] When the axial chirality of these rings is combined with chiral threads, the multipoint interactions between the mechanically linked components are in the origin of the good anion binding enantioselectivities achieved by such species, [32] and it have been also shown to determine useful kinetic effects of its diastereoisomerism on dethreading rates.…”