Palladium-catalyzed substitution of esters of naphthylmethanols, 1-naphthylethanols, and analogues by sodium dimethyl malonate. Stereoselective synthesis from enantiomerically pure substrates

Production of Csp3–Csp3 Bonds through Palladium‐Catalyzed Tsuji–Trost‐Type Reactions of (Hetero)Benzylic Substrates

“…-Hydride elimination was detected from methyl 1-(naphthalen-2-yl)ethyl carbonates [Equation (3)]. [18] This side-reaction became the main reaction pathway from the acetate or carbonate of 1-acenaphthenol [Equation (4)], as well as from carbonates of 1-(anthracen-9-yl)ethanol and 1-(pyren-1-yl)ethanol.…”

“…[5] Under these conditions, lower yields were obtained in THF, MeCN, N,N′-dimethylpropyleneurea, and dioxane. [18] Various catalytic systems were tested in THF: switching either from Pd(dba) 2 to Pd(OAc) 2 or from DPPE to PPh 3 led to ineffective reactions. -Hydride elimination was detected from methyl 1-(naphthalen-2-yl)ethyl carbonates [Equation (3)].…”

“…[18] Addition of the catalyst to Sconfigured substrate 15A proceeds at the stereoface opposite to that of the leaving group, [52] yielding the η configured product. [53] The racemization is due to a S N 2-type nucleophilic addition of free Pd 0 to 15B, leading to 15C.…”

Reductive Coupling of Allylic Esters with Carbonyl Compounds Mediated by the Mischmetall/[SmI2/Pd0cat.′]cat. System

“…[20] Allylic carbonates were prepared according to the procedure of Trost et al; [24] allylic phosphates were prepared using the same procedure. [25] All reactions were carried out under argon in Schlenk tubes using standard vacuum-line techniques.…”

Stereospecific Nickel‐Catalyzed Cross‐Coupling Reactions of Alkyl Grignard Reagents and Identification of Selective Anti‐Breast‐Cancer Agents

“…We next examined the impact of catalyst loading on es, since in related transformations our laboratory had observed an inverse correlation between catalyst loading and stereochemical fidelity. [10] We hypothesized that, in analogy to palladium-catalyzed allylic [11] and benzylic [12] substitution reactions, the key π-benzylnickel intermediate could be racemized by nucleophilic attack of a second nickel species (vide infra). [13] We were pleased to see that lower catalyst loadings do provide higher es; employing 2 mol % Ni(dppe)Cl 2 afforded the desired product in >99% es without a drop in yield (entry 16).…”