Different types of chiral “privileged” ligands 1 and 2 in promoting enantioselective addition of allylating agents to aliphatic and aromatic aldehydes are described. Here, a new concept in the asymmetric allylation reaction is presented. Redox [Cr(Salen)] mediated addition of allyl halides to carbonyl compounds is described, and mechanistic investigations are discussed. These results open acces...

Medium-ring ethers of various structural types have been isolated from marine organisms.1 While medium-ring ethers such as the ladder ether toxins have important implications with regard to their biological impact, it is the exquisite structures of naturally occurring medium-ring ethers that has provoked the imagination of synthetic chemists. Because eight-membered cyclic ethers are more preval...

The asymmetric total synthesis of pyranicin (1) is reported. The butenolide ring was constructed via an asymmetric alkylation/ring-closing metathesis strategy. The three stereocenters in the left-hand tetrahydropyran ring were installed by sequential chiral auxiliary-mediated aldol reactions. Closure of the tetrahydropyran and fusion of the alkyl backbone were affected via a sequential ring-clo...

The use of asymmetric synthetic methodologies plays a crucial role, nowadays, in the preparation of bioactive or other interesting compounds [...].

The asymmetric synthesis of N-allylic indoles is important for natural product synthesis and pharmaceutical research. The regio- and enantioselective N-allylation of indoles is a true challenge due to the favourable C3-allylation. We develop here a new strategy to the asymmetric synthesis of N-allylic indoles via rhodium-catalysed N-selective coupling of aryl hydrazines with allenes followed by...

Studies towards the synthesis of epothilone A via organoboranes have been described. A modified procedure for the large-scale preparation of B-gamma,gamma-dimethylallyldiisopinocampheylborane from prenyl alcohol has been developed. This reagent, upon reaction with various aldehydes, provides the corresponding alpha,alpha-dimethylhomoallylic alcohols in high enantioselectivities. The application...