Enantioselective Michael addition of aldehydes to maleimides organocatalysed by chiral 1,2-diamines: an experimental and theoretical study

Simple and commercially available chiral 1,2-diamines were used as organocatalysts for the enantioselective conjugate addition of aldehydes, including α,α-disubstituted, to maleimides. The reaction was carried out in the presence of hexanedioic acid as an additive in aqueous solvents at room temperature. By employing (1S,2S)- and (1R,2R)-cyclohexane-1,2-diamine as organocatalysts, the corresponding Michael adducts bearing new stereocenters were obtained in high or quantitative yields with enantioselectivities of up to 92%, whereas the use of (1S,2S)-1,2-diphenylethane-1,2-diamine gave a much lower ee. Theoretical calculations were used to justify the observed sense of the stereoinduction.

Enantioselective Synthesis of Succinimides by Michael Addition of Aldehydes to Maleimides Organocatalyzed by Chiral Primary Amine-Guanidines

The monoguanylation of (1S,2S)- and (1R,2R)-cyclohexane-1,2-diamine affords chiral primary amine-guanidines that are used as chiral organocatalysts in the enantioselective Michael addition of aldehydes, particularly α,α-disubstituted aldehydes, to maleimides. The reaction is carried out in the presence of imidazole, as an additive, in aqueous N,N-dimethylformamide, as the solvent, and affords the corresponding enantioenriched succinimides in high or quantitative yields with enantioselectivities up to 96 % ee. Theoretical calculations (DFT and M06–2X) suggest a different hydrogen-bonding coordination pattern between the maleimide (C=O) and the catalyst (NH groups) is responsible for the enantioinduction switch that is observed when the reaction is carried out using primary amine-guanidines versus primary amine-thioureas as the organocatalysts.

Enantioselective Synthesis of Succinimides by Michael Addition of 1,3-Dicarbonyl Compounds to Maleimides Catalyzed by a Chiral Bis(2-aminobenzimidazole) Organocatalyst

A wide variety of chiral succinimides have been prepared in high yields and enantioselectivities by asymmetric conjugate addition of 1,3-dicarbonyl compounds to maleimides under very mild reaction conditions using a bifunctional benzimidazole-derived organocatalyst. Computational and NMR studies support the hydrogen-bonding activation role of the catalyst and the origin of the stereoselectivity of the process.

Solvent-dependent enantioswitching in the Michael addition of α,α-disubstituted aldehydes to maleimides organocatalyzed by mono-N-Boc-protected cyclohexa-1,2-diamines

Enantiomerically pure mono-N-Boc-protected trans-cyclohexa-1,2-diamines are used as organocatalysts for the enantioselective conjugate addition of α,α-disubstituted aldehydes to maleimides. Using a single enantiomer of the organocatalyst, both enantiomeric forms of the resulting Michael adducts bearing a new quaternary stereocenter are obtained in high yields, by only changing the reaction solvent from chloroform (up to 86% ee) to aqueous DMF (up to 84% ee).

Letters from Michael Hogan to William Tudor,

Four letters discussing news of friends and domestic politics and the presidential election, in addition to trade and purchases of certain goods.

Letters from Michael Hogan to William Tudor,

Four letters regarding unrest in Chile, the election of Vice President Joaquín Vicuña and inception of the Chilean Civil War, and subsequent events related to the war.

Deed of feoffment for property in Cambridge, Massachusetts: from Thomas Sweetman to Michael Spencer, 1677 December 10

In this deed of feoffment, written on Dec. 10, 1677, Thomas Sweetman agreed to sell his dwelling house, barn, and orchard to his son-in-law, Michael Spencer, for the cost of eighty pounds sterling. The property was located in Cambridge, Massachusetts, on what was then the northwest corner of the grounds of Harvard College, and was sold "together with the wood lot upon the rocks and cow commons belonging to it." The deed specifies that both Sweetman and his wife Isabel were to be allowed to occupy the property until their deaths, and further explains that Spencer and his family were already living in the dwelling house, occupying three rooms. The document was signed, sealed, and delivered in the presence of Daniel Gookin, Jr. and John Bridgham. It was also signed by Thomas Sweetman.

Europäische Integration aus historischer Erfahrung. Ein Zeitzeugengespräch mit Michael Gehler = European Integration as historical experience. Discussion with Michael Gehler. ZEI Discussion Paper C220, 2013

No abstract.

Europäische Integration aus historischer Erfahrung. Ein Zeitzeugengespräch mit Michael Gehler = European integration as historical experience. Discussion with Michael Gehler. ZEI Discussion Paper C221 2014

No abstract.

Europäische Integration aus historischer Erfahrung, Ein Zeitzeugengespräch mit Michael Gehler = European integration from a historical experience, A Discussion with Michael Gehler. ZEI Discussion Paper C227, 2015

From 1995 to 1999 Monika Wulf-Mathies served as EU commissioner responsible for regional and cohesion policy. She tells us the story of the EU Commission under President Jacques Santer with regard to the historical development of the preparation of the Economic and Monetary Union (EMU), the Union Treaty of Amsterdam (1999) and the EU-Eastern Enlargement. She touches also controversial aspects of the Santer Commission, which led to her collective demission in 1999. According to Wulf-Mathies the increase of EU's democracy deficit is result of an erosion process of the common institutions caused by the nation states which contributed to their weakness. The democratic substance of the union suffers because of the 'summarization' of the EU decision making processes. Monika Wulf-Mathies argues in favor of the community method, which needs revitalization. She proposes European democracy enforcement and transfers of the national budget und economy policies to EU bodies. This eyewitness talk offers an actual EU analysis as well as an assessment of the Santer Commission.