Catalytic asymmetric synthesis of enantioenriched α-deuterated pyrrolidine derivatives

Ru Supported on p-phthalic acid-Mn Derived from a Mn Metal-Organic Framework for Thermo- and Electrocatalytic Synthesis of Ethylene-D4 Glycol

Deuterium-labeled polyols are one of the most extensive applied chemicals in biochemistry and biophysics. However, the deuteriation still is insufficient, exhibiting a low deuterated ratio and indistinct reaction mechanism. Herein, Ru supported on MnBCD (MnBDC, derived from Mn p-phthalic acid metal-organic framework) as nanocatalyst with an agglomerated sheet-type structure; this allows the possibility of achieving both thermo- and electrocatalytic hydrogen isotope exchange (HIE) reaction. Furthermore, XPS characterization confirmed that the specific structural changes in the electron density of Ru outer layers were modulated through the impregnation and reduction processes. According to the change of outer electronic structure, hydrogen spillover and electron-rich flow promote the reaction of the catalyst in thermo- and electrocatalytic systems, respectively. In addition, the results indicate that a high deuterated ratio of 97 % can be obtained, hence the catalytic technology has enormous potential for the synthesis of a broad variety of deuterium-labeled compounds.

Electron-rich benzofulvenes as effective dipolarophiles in copper(i)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides

A series of benzofulvenes without any electron-withdrawing substituents were employed as 2π-type dipolarophiles for the first time to participate in Cu(i)-catalyzed asymmetric 1,3-dipolar cycloaddition (1,3-DC) reactions of azomethine ylides. An intrinsic non-benzenoid aromatic characteristic from benzofulvenes serves as a key driving force for activation of the electron-rich benzofulvenes. Utilizing the current methodology, a wide range of multi-substituted chiral spiro-pyrrolidine derivatives containing two contiguous all-carbon quaternary centers were formed in good yield with exclusive chemo-/regioselectivity and high to excellent stereoselectivity. Computational mechanistic studies elucidate the origin of the stereochemical outcome and the chemoselectivity, in which the thermostability of these cycloaddition products is the major factor.

Straightforward and Efficient Deuteration of Terminal Alkynes with Copper Catalysis

The mild and effective preparation of deuterated organic molecules is an active area of research due to their important applications. Herein, we report an air-stable and easy to access copper(I) complex as catalyst for the deuteration of mono-substituted alkynes. Reactions were carried out in technical solvents and in the presence of air, to obtain excellent deuterium incorporation in a range of functionalised alkynes.

Catalytic asymmetric deuterosilylation of exocyclic olefins with mannose-derived thiols and deuterium oxide

Metal-free, photoinduced asymmetric deuterosilylation of exocyclic olefins has been achieved using a mannose-derived thiol catalyst.

Stereodivergent Synthesis of Enantioenriched α-Deuterated α-Amino Acids via Cascade Cu(I)-Catalyzed H-D Exchange and Dual Cu- and Ir-Catalyzed Allylation

A one-pot Cu-mediated H-D exchange with inexpensive heavy water as the deuterium source, followed by Cu- and Ir-catalyzed stereodivergent allylic alkylation, has been developed, providing efficient access to enantioenriched α-deuterium-labeled α-amino acids from readily available glycine imine esters in a high yield with excellent stereoselectivity. High deuterium enrichment, exquisite regioselectivity, precise stereoselectivity control, and operationally convenient procedures make this protocol appealing for the preparation of highly synthetically useful α-deuterated α-amino acids.