Catalytic Stereospecific Allyl–Allyl Cross-Coupling of Internal Allyl Electrophiles with AllylB(pin)

Abstract

Application of internal electrophiles in catalytic stereospecific allyl–allyl cross-coupling enable the rapid construction of multisubstituted 1,5-dienes, including those with all carbon quaternary centers. Compounds with minimal steric differentiation can be synthesized with high enantiomeric excess.

Enantioselective and Enantiospecific Transition-Metal-Catalyzed Cross-Coupling Reactions of Organometallic Reagents To Construct C–C Bonds

“… 339 More recently, the Morken laboratory reported the Pd-catalyzed stereospecific substitution of allylic acetate 464 with allyl pinacol boronate to deliver enantioenriched 1,5-diene 465 in good yield and with excellent es ( Figure 89 b). 340 This reaction can also be applied to tertiary acetates, which enables the production of 1,5-dienes bearing all-carbon quaternary centers. This transformation provides a notable alternative to the Cope rearrangement for the synthesis of chiral 1,5-dienes, particularly because there are no enantioselective examples of Cope rearrangements of unfunctionalized substrates (such as those required to produce 465 ).…”

“…The authors have also disclosed a related kinetic resolution, in which a chiral ligand enables the selective allylation of one enantiomer of the propargylic substrate, allowing recovery of enantioenriched starting material . More recently, the Morken laboratory reported the Pd-catalyzed stereospecific substitution of allylic acetate 464 with allyl pinacol boronate to deliver enantioenriched 1,5-diene 465 in good yield and with excellent es (Figure b) . This reaction can also be applied to tertiary acetates, which enables the production of 1,5-dienes bearing all-carbon quaternary centers.…”

Palladium-Catalyzed Oxidative Rearrangement of Tertiary Allylic Alcohols to Enones with Oxygen in Aqueous Solvent

“…1 H NMR (400 MHz, CDCl 3 ) δ 7.37 -7.29 (m, 4H), 7.24 (ddd, J = 6.8, 3.9, 1.6 Hz, 1H), 6.01 (d, J = 1.7 Hz, 1H), 4.61 (dd, J = 6.8, 2.9 Hz, 1H), 2.67 (dd, J = 14.8, 6.7 Hz, 1H), 2.47 (dd, J = 20.7, 6.4 Hz, 1H), 2.09 -1.98 (m, 1H), 1.92 -1.71 (m, 5H), 1.45 (ddd, J = 12.9, 11.4, 4.7 Hz, 1H). 13 3-Butylcyclohept-2-en-1-ol (2p) 12 : Colorless oil (136 mg, 81%), with 10% (17 mg) of 1p recovered. Rf = 0.37 (hexane / EtOAc = 6 / 1).…”

Recent development of allyl–allyl cross-coupling and its application in natural product synthesis

“…In 2014, they investigated 40 the Pd-catalyzed allyl–allyl cross-coupling reaction using internal allyl electrophiles, which allowed the rapid construction of substituted 1,5-dienes including those with all carbon quaternary centers with high regio- and enantioselectivity (Scheme 6). Notably, an important feature of the cross-coupling reactions is that Pd is generally unable to migrate from one allyl-face to the other.…”