Enantioselective allylations of selected alpha, beta, gamma, delta-unsaturated aldehydes by axially chiral N,N'-dioxides. Synthesis of the left-hand part of papulacandin D

0471657 - ÚOCHB 2017 RIV NL eng J - Článek v odborném periodiku
Vlašaná, K. - Betík, R. - Valterová, Irena - Nečas, D. - Kotora, M.
Enantioselective allylations of selected alpha, beta, gamma, delta-unsaturated aldehydes by axially chiral N,N'-dioxides. Synthesis of the left-hand part of papulacandin D.
Current Organocatalysis. Roč. 3, č. 3 (2016), s. 301-305. ISSN 2213-3372
Institucionální podpora: RVO:61388963
Klíčová slova: allylation * aldehyde * Lewis base * asymmetric synthesis * organocatalysis * homoallylic alcohols
Obor OECD: Organic chemistry

Allylations of several structurally different alpha, beta, gamma, delta-aldehydes were carried out in various solvents in the presence of a catalytic amount of an N,N’-dioxide to access conditions leading to the highest symmetric induction. Out of screening of several reaction conditions the highest asymmetric induction (up to 98% ee) was achieved in THF. A higher asymmetric induction was observed with substrates bearing additional substituents on alpha-carbon atom. Allylation of (S)-(2E,4E)-2,8-dimethyldecadienal gave rise to the corresponding homoallylic alcohol with a high asymmetric induction of 92% ee. The method is useful for synthesis of valuable building block for organic synthesis as it was demonstrated by a synthesis of a papulacandin D intermediate.
Trvalý link: http://hdl.handle.net/11104/0269015