Strikingly Simple Direct α-Allylation of Aldehydes with Allyl Alcohols:  Remarkable Advance in the Tsuji−Trost Reaction

Direct Catalytic Intermolecular α‐Allylic Alkylation of Aldehydes by Combination of Transition‐Metal and Organocatalysis

“…For example, Tamaru and co-workers reported that the a-allylic alkylation of aldehydes is possible in the presence of a catalytic amount of palladium and a slight excess of Et 3 B. [8] Most recently, transition-metal catalysis was employed in the a-alkylation of ketone enolates with alcohols. [9] Organocatalysis is a fast forward-moving research field.…”

Amphiphilic Allylic Alkylation with Allyl Alcohols Promoted by Pd-Catalyst and Triethylborane

“…Under the Pd/Et 3 B reaction system, α-allylation of alkyl aldehydes can be readily achieved by direct use of aldehydes and allylic alcohols. The secondary alkyl aldehyde cyclohexanecarbaldehyde nicely reacts with a wide structural variety of allylic alcohols to provide α-allylated cyclohexanecarbaldehydes (Scheme 9) [14]. Primary alkyl aldehydes showed quite different reaction features (Scheme 10).…”

Activation of Allyl Alcohols as Allyl Cations, Allyl Anions, and Amphiphilic Allylic Species by Palladium

“…[17] In this context, the alkylation recorded in Run 4 in Scheme 8, directly with an aldehyde and an allyl alcohol, is remarkable. [18] Under the usual Pd/Et 3 B conditions (Run 1), cyclohexanecarbaldehyde provides a mixture of C2 alkylation (6) and C1 alkylation (7) products, together with a cinnamyl alcohol homocoupling product 9. In this reaction, additives play decisive roles: Et 3 N increases the yield of 6, while LiCl impedes the reaction.…”