Catalytic S_N2′-Selective Substitution of Allylic Chlorides With Arylboronic Esters

Abstract

A copper-catalyzed S(N)2'-selective arylation of allylic chlorides has been achieved using arylboronic esters as nucleophiles. Arylation products were obtained in high yield with a variety of allylic chlorides and arylboronic esters in the presence of a wide range of functional groups. A mechanism is proposed on the basis of the results of stoichiometric experiments and the isolation of the proposed intermediate.

Gold(I)‐catalyzed Benzylation of (Hetero)aryl Boronic Acids with (Hetero)benzyl Bromides by the Strategy of a SN2‐type Reaction

“…We proposed two possible reaction patterns of this step. In the first reaction pattern, the naphthyl moiety of Int1 acting as a nucleophile, whose C 1 position was activated by gold catalyst, attacks 2 a through a S N 2 pathway that is similar to the reported mechanism of copper‐catalyzed allylation of arylboronates . The transition state of this process is TS1 with an energy barrier of 24.6 kcal mol −1 .…”

Enantiospecific, Nickel-Catalyzed Cross-Couplings of Allylic Pivalates and Arylboroxines

“…For example, formation of enantioenriched products via Cu-catalyzed allylic arylations largely relies on the use of Grignard, organozinc, or organoaluminum reagents; 12−16 only a limited number of methods allow the use of arylboronates. 17−19 …”

Copper‐Catalyzed Asymmetric Allylic Substitution of Allyl Phosphates with Aryl‐ and Alkenylboronates

“…[10] In 2010, two research groups independently reported that arylboronic acid esters are competent nucleophiles in coppercatalyzed allylic substitution reactions using achiral catalysts. [11] Based on this precedent, as well as our recent success in the copper-catalyzed asymmetric addition of organoboronates using Mauduit-type chiral N-heterocyclic carbene (NHC) ligands, [12,13] we initially conducted the reaction of cinnamyl phosphate (1 a) with 4-methoxyphenylboronic acid neopentylglycol ester in the presence of CuCl (5 mol %), chiral NHC salt (S)-4 a (5.5 mol %), [12a] and KOtBu (2.0 equiv) in THF at 30 8C (Table 1, entry 1). Under these reaction conditions, the reaction proceeded smoothly to give a 41:59 mixture of the g-substitution product 2 a and the a-substitution product 3 a in 95 % combined yield; the thus obtained 2 a had a moderate ee value of 56 %.…”