The development of suitable chiral catalysts, which represent powerful, economically feasible tools for the preparation of optically active organic molecules, is a fundamental endeavour in synthetic chemistry. Chiral phosphoric acids derived from axially chiral 1,1'-bi-2-naphthol (BINOL) are a widely used class of strong Brønsted acid catalysts and have been applied successfully in many asymmetric catalyzed reactions. Accordingly, the development and application of chiral spirocyclic phosphoric acids derived from axially chiral 1,1'-spirobiindane-7,7'-diol (SPINOL) have received increasing attention in the last eight years. This review covers the synthetic methods and the application of chiral spirocyclic phosphoric acids in asymmetric catalysis.

No abstract

We address the time evolution of quantum correlations (QCs) such as entanglement, purity, and coherence for a model of two non-interacting qubits initially prepared as a maximally entangled bipartite state. We contrast the comparative potential of the classical fields to preserve these QCs in the noisy and noiseless realms. We also disclose the characteristic dynamical behavior of the QCs of the two-qubit state under the static noise effects originating from the common and different configuration models. We show that there is a direct connection between the fluctuations allowed by an environment and the preservation of QCs. Due to the static noise dephasing effects, the QCs are suppressed, resulting in the separability of the two-qubit entangled state after a finite duration. For bipartite QCs preservation, we show that the common configuration is more resourceful than the different configuration. Furthermore, this protection of the QCs under static noise for large intervals is entirely attributable to the existence of the entanglement sudden death and birth phenomenon. Most importantly, we found the bipartite QCs less fragile than the tripartite ones in comparison under the static noise. In addition, we find the concurrence measure to show more evident revivals of entanglement in comparison.

No abstract

A general, efficient, highly enantio-and chemoselective N-heterocyclic carbene (NHC)/Ni-catalyzed addition of readily available and stable arylboronic esters to ketones is reported. This protocol provides unexpectedly fast access (usually 10 min) to various chiral tertiary alcohols with exceptionally broad substrate scope and excellent functional group tolerance (76 examples, up to 98 % ee). This process is orthogonal to other known Ni-mediated Suzuki-Miyaura couplings, as it tolerates aryl chlorides, fluorides, ethers, esters, amides, nitriles, and alkyl chlorides. The reaction is applied to late-stage modifications of various densely functionalized medicinally relevant molecules. Preliminary mechanistic studies suggest that a rare enantioselective h 2-coordinating activation of ketone carbonyls is involved. This crosscoupling-like mechanism is expected to enable other challenging transformations of ketones.