Synthesis of unsaturated β-amino acid derivatives from carbamates of the Baylis–Hillman products

Phosphine-catalyzed intramolecular γ-umpolung addition of α-aminoalkylallenic esters: facile synthesis of 3-carbethoxy-2-alkyl-3-pyrrolines

“…For this purpose, we turned to a known tertiary amine-catalyzed rearrangement of allylic N -tosyl carbamates and tested it on the similar, but never before utilized, allenylic- N -tosyl carbamates 3 . 12,13 We were pleased to discover that treatment of the allenylic carbamates with a nucleophilic catalyst facilitated the desired rearrangement. The reaction was best facilitated by slowly adding the allenylic carbamate to a solution of one equivalent of DABCO (Table 1).…”

New, Simple and Versatile Synthesis of Protected α-Alkylidene-β-amino Acids from Activated Vinylphosphonates

“…A Baylis-Hillman reaction was performed with acrylates or acrylonitrile as activated olefins and imines 2,10 or enantiomerically pure osubstituted benzaldehyde imine Cr(CO) 3 complexes. 11 Baylis-Hillman adducts were usually converted into allyl bromides 12 or acetates 13 and reacted with amines or further transformed into trichloroacetimidates 9,14 or carbamates 15 and treated with a base. Another, well documented approach to 1 is conjugate addition of R 2 CuLi 16,17 or DIBAL-H 3 to 2-alkynoates followed by nucleophilic addition of thus formed organometallic intermediates to imines.…”

Decarboxylative Organocatalytic Allylic Amination of Morita–Baylis–Hillman Carbamates

“…Because carbamates andc arbamic acids can easily undergo decarboxylation to generate the corresponding amines, [11] we begant esting the reactivity of racemic aniline-derived carbamates 1 in decarboxylative allylic amination using conventional nitrogenand phosphine nucleophilesa scatalysts (Table 1). Fortunately,t he model reaction of 1a performed in toluenea t room temperature was efficiently catalyzed with 1,4-diazobicyclo [2.2.2]octane (DABCO), generatinga llylic amine 2a in an almost quantitative yield.…”