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An array of enantioenriched vinyl boronates bearing an allylic carbonate moiety have been prepared through selective hydroboration of propargyl carbonates. Treatment of these vinyl boronates with TBAF in THF affords enantioenriched 1,3‐disubstituted allenes through a novel 1,2‐anti elimination in good yields and high enantiospecificities. [ABSTRACT FROM AUTHOR]

The hydroboration of CO2 into bis(boryl)acetal (BBA) compounds is an important transformation, since it enabled to selectively reduce CO2 by 4e‐and to subsequently use the BBA compounds as C1 and Cn sources. However, the influence of the nature of the boryl moieties on the reactivity of BBA compounds has not been evaluated so far. In the present study, four BBA compounds – including two new ones – were reacted with 2,6‐diisopropylaniline to afford the expected imine. Significant differences in the rate of the reaction from minutes to weeks have been observed depending on the BBA used, showing the importance of the nature of the boryl moieties. Theoretical investigations enabled to propose a mechanism involving the addition of the aniline to the BBA as the rate‐determining step and to determine that the steric hindrance of the BBA compounds is the main factor driving the rate of this condensation reaction. [ABSTRACT FROM AUTHOR]

Chiral α-allenols are prepared with high diastereocontrol through an unprecedented and spontaneous β-oxygen elimination of an α-epoxy vinyl boronate. Stochiometric experiments and DFT calculations support a dual role of the copper catalyst, which orchestrates the hydroboration and the syn-elimination step. [ABSTRACT FROM AUTHOR]

The asymmetric synthesis of tricyclic compounds by the desymmetrization of cyclohexadienones is presented. The reaction tolerated a large variety of substituents at different positions of the cyclohexadienone, and heterocyclic rings of different sizes were accessible. Density functional theory calculations showed that the reaction proceeds through an asynchronous [4+2] cycloaddition. [ABSTRACT FROM AUTHOR]

The article offers information on the organocatalytic synthesis of 3,4-disubstituted pyrroles by a cascade of reactions. During the cascade of reactions, an adduct intermediates formation takes place before the 3,4-disusstituted pyrroles formation. The adducts then react with an amine and undergo a series of reactions to form the pyrroles.

Dihydroarylfuran skeletons are efficiently synthesized from (Z)-bromonitroalkenes and naphthol derivatives in good yields and excellent enantioselectivities by using squaramide catalysis. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Highly Enantioselective Construction of Tricyclic Derivatives by the Desymmetrization of Cyclohexadienones" by C. Martin-Santos and others, published in the periodical "Angewandte Chemie International Edition" in 2014.

Enantiopure trans-dihydroarylfurans (II), (V) and (VII) are synthesized from (Z)-bromonitroalkenes (II) and naphthol (I) or phenol derivatives (IV) and (VI), resp., in good yields and high enantioselectivity by using a squaramide catalyst. [ABSTRACT FROM AUTHOR]

A new organocatalytic synthesis of 3,4-disubstituted pyrroles is presented, involving the one-pot, two-step reaction of aldehydes, e.g. (I), with gem-bromonitroalkenes, e.g. (II), and amines, e.g. (III). [ABSTRACT FROM AUTHOR]