Pd-catalyzed asymmetric allylic alkylation of 2-substituted cycloalkenyl carbonates using a chiral diaminophosphine oxide: (S,RP)-Ph-DIAPHOX

A Pd-catalyzed asymmetric allylic alkylation of 2-substituted cycloalkenyl carbonates using a chiral diaminophosphine oxide is described. Asymmetric allylic substitution of various cyclic substrates proceeded using 5 mol % of Pd catalyst, 10 mol % of (S,RP)-Ph-DIAPHOX 1, 10 mol % of LiOAc, and N,O-bis(trimethylsilyl)acetamide (BSA), to afford the corresponding products in excellent yields with up to 92% ee.

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(1R)-2-Phenyl-2-cyclohexen-1-yl malonic acid dibenzyl esterC29H28O4Ee = 86%[α]D24=-35.4 (c 0.32, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(1R)-2-Phenyl-2-cyclopenten-1-yl malonic acid dibenzyl esterC28H26O4Ee = 89%[α]D19=-43.2 (c 0.87, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)