Quantitative Prediction of the Rate of Protodeboronation by a Mechanistic Density Functional Theory-Aided Algorithm.

Computational reaction prediction has become a ubiquitous task in chemistry due to the potential value accurate predictions can bring to chemists. Boronic acids are widely used in industry; however, understanding how to avoid the protodeboronation side reaction remains a challenge. We have developed an algorithm for prediction of the rate of protodeboronation of boronic acids.

Synthesis of Electron-Deficient Heteroaromatic 1,3-Substituted Cyclobutyls via Zinc Insertion/Negishi Coupling Sequence under Batch and Automated Flow Conditions.

Synthesis of 1,3-substituted cyclobutyls enabled by zinc insertion into functionalized iodocyclobutyl derivatives followed by Negishi coupling with halo-heteroaromatics is reported. Two distinct sets of conditions were developed; the first involved a two-step batch protocol using activated Rieke zinc, and the second involved a multistep continuous flow process. Both methods showed complementarity and allowed for rapid access to these medicinally relevant motifs, the possibility of scaling up, and automation for library synthesis.

Enantioselective and Regiodivergent Copper-Catalyzed Electrophilic Arylation of Allylic Amides with Diaryliodonium Salts.

A catalytic enantioselective and regiodivergent arylation of alkenes is described. Chiral copper(II)bisoxazoline complexes catalyze the addition of diaryliodonium salts to allylic amides in excellent ee. Moreover, the arylation can be controlled by the electronic nature of the diaryliodonium salt enabling the preparation of nonracemic diaryloxazines or β,β'-diaryl enamides.

Gram-scale enantioselective formal synthesis of morphine through an ortho-para oxidative phenolic coupling strategy.

A gram-scale catalytic enantioselective formal synthesis of morphine is described. The key steps of the synthesis involve an ortho-para oxidative phenolic coupling and a highly diastereoselective "desymmetrization" of the resulting cyclohexadienone that generates three of the four morphinan ring junction stereocenters in one step. The stereochemistry is controlled from a single carbinol center installed through catalytic enantioselective hydrogenation.

Enantio- and regioselective conjugate addition of organometallic reagents to linear polyconjugated nitroolefins.

The copper-catalysed conjugate addition of trialkylaluminium and dialkylzinc reagents to polyconjugated nitroolefins (nitrodiene and nitroenyne derivatives) is reported. A reversed Josiphos ligand L7 allows for the selective 1,4- or 1,6-addition with high enantioselectivities.

Direct trapping of sterically encumbered aluminum enolates.

The formation of chiral and sterically congested cyclohexanone derivatives has been achieved through a multistep sequence with one single purification step. (n-Butoxymethyl)-diethylamine was identified as a highly efficient reagent for the direct trapping of aluminum enolates. The Lewis acidic character of aluminum suffices to activate the α-aminoether to form in situ an electrophilic iminium species.

Formation of quaternary stereogenic centers by NHC-Cu-catalyzed asymmetric conjugate addition reactions with Grignard reagents on polyconjugated cyclic enones.

The copper-catalyzed conjugate addition of various Grignard reagents to polyconjugated enones (dienone and enynone derivatives) is reported. The catalyst system, composed of copper triflate and an NHC ligand, led to the unusual selective formation of the 1,4-addition products. This reaction allows for the creation of all-carbon chiral quaternary centers with enantiomeric excesses up to 99%.

New experimental conditions for tandem hydroalumination/Cu-catalyzed asymmetric conjugate additions to β-substituted cyclic enones.

Readily available alkenylalanes, arising from hydroalumination of unprotected terminal alkynes, have been directly employed for the copper-catalyzed asymmetric conjugate addition (ACA) to β-substituted cyclic enones. The desired products, containing a quaternary stereogenic center, are generally obtained in good yields and enantioselectivities.

Highly enantioselective and regioselective copper-catalyzed 1,4 addition of grignard reagents to cyclic enynones.

In this letter we describe an unusual result in terms of regioselectivity with respect to copper-catalyzed conjugate additions of various Grignard reagents to cyclic enynones. The use of Cu(OTf)(2) and NHC ligand L1 as the catalyst combination in CH(2)Cl(2) led to the unique formation of the 1,4 adduct. This selectivity does not follow the general trend previously observed in the literature using extended Michael acceptors.

Enantioselective and regiodivergent copper-catalyzed conjugate addition of trialkylaluminium reagents to extended nitro-Michael acceptors.

The first highly enantioselective and regiodivergent conjugate addition of trialkylaluminium reagents to nitrodienes and nitroenynes is described. By a design of the substrate and a fine-tuning of the reaction conditions, it is possible to selectively form the 1,4- or 1,6-adduct. The same combination of catalyst, copper source, and a ferrocene-based phosphine ligand afforded enantioselectivities up to 95% and 91%, respectively.

First enantioselective organocatalytic conjugate addition of aldehydes to vinyl phosphonates.

Chiral amines catalyze the enantioselective conjugate addition of aldehydes to vinyl phosphonates in high yields and with enantioselectivities up to 97% ee. This novel process provides synthetically useful chiral gamma-geminal phosphonate aldehydes which can be easily converted in a few steps into chiral beta-substituted vinyl phosphonates with conservation of the optical purity.