102369-06-2

The first total syntheses of 9-epoxyfalcarindiol 1a and its diastereomer 1b have been achieved. Central to our approach were the Zn-cyclopropane-based amino alcohol catalyzed enantioselective alkynylation of acrolein, the diastereoselective addition of a diynic ester to an epoxy aldehyde, and the asymmetric Sharpless epoxidation of allylic alcohol catalyzed with L-(+)-diethyl tartrate and Ti(OiPr)4.

A highly stereoselective synthesis of (+)-Virol C (1) has been achieved starting from octan-1-ol (6) using two different strategies, elimination reactions of epoxyallyl chloride 12 and epoxy chloride 16 to hydroxyenyne 2 and trans-hydroxyalkenyl chloride 4 as key reactions in route a and route b, respectively.

Cathepsin K (CatK) is a cysteine protease known for its potent collagenolytic activity, being recognized as an important target to the development of therapies for the treatment of bone disorders. Epoxypeptidomimetics have been reported as potent inhibitors of cathepsins, thus in this work we present a green synthesis of new peptidomimetics by using a one-pot asymmetric epoxidation/Ugi multicomponent reaction. The compounds were evaluated against CatK showing selectivity when compared with cathepsin L, with an inhibition profile in the low micromolar IC50 range. Investigation of the mechanism of action carried out for compounds LSPN428 and LSPN694 suggested a mixed inhibition mode and docking studies allowed a better understanding about interactions of inhibitors with the enzyme.

Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogen peroxide as the oxidant, we have developed highly enantioselective Weitz-Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonyl compounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5-15-membered cyclic enones, and α-branched enals as substrates. In addition to an expanded scope, synthetic applications of the products are presented. We also report detailed mechanistic investigations of the catalytic intermediates, structure-activity relationships of the cinchona amine catalyst, and rationalization of the absolute stereoselectivity by NMR spectroscopic studies and DFT calculations.

An eco-friendly synthesis of highly functionalized epoxides and their incorporation into an organocatalytic multicomponent approach are reported. For this, a modified class of diarylprolinol silyl ethers was designed to enable high catalytic activity in an environmentally benign solvent system. The one-pot procedure showed great efficiency in promoting stereoselective multicomponent transformations in a tandem, 'green' fashion. Because of its non-residual, efficient and selective character, this synthetic design shows promise for large-scale applications in both diversity and target-oriented syntheses. The Royal Society of Chemistry 2012.

Two sides of the same coin: Syn and anti 1,4-diols have been synthesized through the regio- and diastereoselective CuI-catalyzed boration of allylic epoxides (see scheme; pin=pinacolato, TES=triethylsilyl). In situ protection of the alcohol all

This study demonstrates the first formal asymmetric trans-dihydroxylation and trans-aminohydroxylation of α,β-unsaturated aldehydes in an organocatalytic multibond forming one-pot reaction cascade. This efficient process converts α,β-unsaturated aldehydes into optically active trans-2,3-dihydroxyaldehydes and trans-3-amino-2-hydroxyaldehydes with the aldehyde moiety protected as an acetal. The elaborated one-pot protocol proceeds via the formation of 2,3-epoxy and 2,3-aziridine aldehyde intermediates, which subsequently participate in a novel NaOMe-initiated rearrangement reaction leading to the formation of acetal protected trans-2,3-dihydroxyaldehydes and trans-3-amino-2-hydroxyaldehydes in a highly stereoselective manner. Advantageously, this multibond forming reaction cascade can be performed one-pot, thereby minimizing the number of manual operations and purification procedures required to obtain the products. Additionally, for the purpose of trans-aminohydroxylation of the α,β-unsaturated aldehydes, a new enantioselective aziridination protocol using 4-methyl-N-(tosyloxy) benzenesulfonamide as the nitrogen source has been developed. The mechanism of the formal trans-dihydroxylation and trans-aminohydroxylation of α,β-unsaturated aldehydes is elucidated by various investigations including isotopic labeling studies. Finally, the products obtained were applied in the synthesis of numerous important molecules.

Optically pure allyl alcohols have been prepared from tosylhydrazones derived from chiral epoxy aldehydes by alkylative elimination utilizing alkyl magnesium reagents.

A highly regioselective reduction of epoxy allylic alcohols to chiral butadienyl alcohols and its application to taxol skeleton is described.

-