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

Abstract

Abstract:The combination of Pd catalyst and triethylborane induces allylic alcohols to undergo direct electrophilic allylation of soft nucleophiles. Similar conditions also accelerate nucleophilic allylations of aldehydes and aldimines to provide homoallyl alcohols and homoallylamines, respectively. Moreover, 2-methylenepropane-1,3-diol undergoes a sequential amphiphilic activation to react with aldehydes and aldimines, giving rise to 3-methylenecyclopentanols and 3-methylenepyrrolidines.

Palladium-Catalyzed [4 + 2] Cycloaddition of Aldimines and 1,4-Dipolar Equivalents via Amphiphilic Allylation

“…π-Allylpalladium can serve as an important intermediate for efficient C–C bond transformations . We have developed the direct formation of π-allylpalladium derived from allylic alcohols promoted by a Pd catalyst and triethylborane; e.g., the activation of allylic alcohols promoted by triethylborane as Lewis acid facilitated oxidative addition toward Pd(0) species to form a π-allylpalladium intermediate serving as an allylic cation equivalent (Scheme ) …”

Intermolecular Dehydrogenative Heck Reactions

“…The authors envisaged the regeneration of the catalyst and the formation of the adduct from 28B via the β-OAc elimination depicted in Scheme , 28B being obtained either directly (path a ) or via 28A . This reaction, published in 2004 and which involves regeneration of the Pd(II) catalyst via the cleavage of the C−OAc bond, contrasts with the 2010 report summarized in eq …”

Gold(I)-catalyzed synthesis of γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with alcohols

“…Despite their undoubted synthetic/economic advantages (i.e., water is the only stoichiometric byproduct produced), the intrinsic lower reactivity of allylic alcohols compared to allyl halides/acetates/carbonates generally necessitates harsher reaction conditions and/or the need for activating agents (i.e., Brønsted or Lewis acids) [3–4]. …”

“…Allylic alcohols are highly desirable, readily available, cheap, and environmental sustainable reaction partners for allylic alkylation reactions in the presence of C- as well as X-based (X: heteroatom) nucleophiles [ 1 – 2 ]. Despite their undoubted synthetic/economic advantages (i.e., water is the only stoichiometric byproduct produced), the intrinsic lower reactivity of allylic alcohols compared to allyl halides/acetates/carbonates generally necessitates harsher reaction conditions and/or the need for activating agents (i.e., Brønsted or Lewis acids) [ 3 – 4 ].…”