Lewis Acid-Promoted Addition of 1,3-Bis(silyl)propenes to Aldehydes: A Route to 1,3-Dienes

Abstract

The Lewis acid-promoted addition of 1,3-bis(silyl)propenes to aldehydes to provide the corresponding (E)-1,3-dienes in excellent stereoselectivity and good to excellent yields is reported. The procedure is mild, base-free, and operationally straightforward.

Stereoselective preparation of (E)- and (Z)-di- and trisubstituted 1,3-butadienes

“…The stereoisomerically pure alcohols 4f-h were transformed into both the (E)-and (Z)-dienes 1 by similar treatment with acid or base with complete stereoselectivity (entries 5-10). 15 The trisubstituted butadienes 1f and g were also obtained with high stereoselectivity by the treatment of highly substituted b-hydroxy silanes 4i and k (entries [11][12][13][14].…”

“…Somfai and co-workers reported the preparation of (E)-1-monosubstituted 1,3-dienes by the Lewis acid-promoted reaction of 1,3-bis(silyl)propenes with aldehydes. 13 However, the application of this method to the preparation of (Z)-1,3-dienes or more highly substituted congeners has not appeared yet.…”

General Preparation of 1‐Substituted (E)‐1,3‐Dienes under Mild Conditions

“…In this regard, the Nozaki–Hiyama16 allylation of aldehydes, followed by a Peterson‐type olefination protocol17 has been used in the total synthesis of a number of natural products that contain a 1,3‐dienic moiety 18. More recently, the stereoselective synthesis of ( E )‐1,3‐dienes by a Lewis‐acid‐promoted addition of 1,3‐bis(silyl)propenes to aldehydes has been described in the literature 19. On the other hand, the reaction of aldehydes with N ‐allylhydrazine derivatives gives 1,3‐dienes with high levels of E stereoselectivity, but this approach is limited to aromatic aldehydes 20.…”

Aza-Peterson Olefinations: Rapid Synthesis of (E)-Alkenes

“…[23][24][25][26] Various groups have reported the synthesis of 1,3-dienes through a Peterson olefination starting from 1,3-bis(trimethylsilyl)propene (Scheme 2a). [27][28][29][30][31] Deprotonation with organolithium bases, in combination with diamine or phosphoramide additives, and addition into carbonyl compounds produces 1,3-diene products in one step, albeit in low yields and poor stereoselectivity. 27,28 Chan and coworkers found that the addition of MgBr2 to the organometallic reagent enabled the isolation of the β-hydroxysilane intermediate, which could be treated under acidic or basic conditions to stereoselectively form (1E, 3E)-or (1E, 3Z)dienes.…”