Synthesis of Fluorine-Containing Cyclic α-Amino Acid and α-Amino Phosphonate Derivatives by Alkene Metathesis

Abstract

The electrophilic imino esters XF 2 CC(=NPG)CO 2 Me and imino phosphonates CF 3 CC(=NPG)P(O)(OR) 2 (PG = SO 2 Ph, Cbz, Boc) were transformed by nucleophilic and then electrophilic additions into fluorine-containing amino esters and amino phosphonates with two pendent alkene chains (XF 2 C)(CH 2 =CH(CH 2 ) n C(NPG)(Z)(CH 2 ) m CH=CH 2 [Z = CO 2 Me, P(O)(OR) 2 ]. The ring-closing metathesis was perfor-

An Actinide Complex with a Nucleophilic Allenylidene Ligand

“…We also examined the reactivity of [Li(2.2.2-cryptand)][ 1 ] toward norbornene and diphenylacetylene in THF- d 8 , however no reaction was observed in either case. In contrast, Dixneuf and co-workers have shown that ruthenium allenylidenes are competent precatalysts for ring-closing metathesis, enyne metathesis, and ring-opening metathesis polymerization. ,,− It is not immediately clear why [Li(2.2.2-cryptand)][ 1 ] is unreactive toward olefins and alkynes, but it may be due to the steric inaccessibility of the Th center caused by the presence of three cyclopentadienyl coligands.…”

An Actinide Complex with a Nucleophilic Allenylidene Ligand

“…We also examined the reactivity of [Li(2.2.2-cryptand)][ 1 ] toward norbornene and diphenylacetylene in THF- d 8 , however no reaction was observed in either case. In contrast, Dixneuf and co-workers have shown that ruthenium allenylidenes are competent precatalysts for ring-closing metathesis, enyne metathesis, and ring-opening metathesis polymerization. ,,− It is not immediately clear why [Li(2.2.2-cryptand)][ 1 ] is unreactive toward olefins and alkynes, but it may be due to the steric inaccessibility of the Th center caused by the presence of three cyclopentadienyl coligands.…”

Asymmetric Synthesis of Cyclic Fluorinated Amino Acids

“…Having in hands these aminodiene compounds, we focused our attention on the synthesis of the correspondingly substituted chiral tetrahydropyridines by a RCM protocol. Some previous works in the literature have already described RCM reactions with CF 3 ‐amines to obtain trifluoromethylated nitrogen heterocycles . Among the commercially available ruthenium‐based alkylidine Grubbs catalysts, we chose the air‐ and moisture‐stable Grubbs' second‐generation catalyst, which was widely used for the synthesis of sterically hindered poly‐substituted dienes, aminodienes, and large‐size rings.…”

Synthesis of trifluoromethyl N , N -aminals from nitrogen containing heterocycles by using a plasma flow microreactor

“…To access a-trifluoromethyl amino derivatives, [7][8][9][10][11][12][13][14][15][16][17][18] N,O-trifluoromethyl acetals A [19][20][21][22] and trifluoromethyl N,N-aminals A 023-25 are useful as the treatment of A and A 0 , under acidic conditions, led to trifluoromethyl iminium intermediates B which can be trapped by a variety of nucleophiles to produce a diversity of a-trifluoromethyl amino derivatives C (Scheme 1, eqn (1)). However, to synthesize N, N-aminals either drastic conditions 23,24 are used (Scheme 1, eqn (2)), or several steps are required to produce these compounds from amines [19][20][21][22] (Scheme 1, eqn (3)), or the use of additives is necessary 25 (Scheme 1, eqn (2)-( 4)).…”

An Actinide Complex with a Nucleophilic Allenylidene Ligand

“…We also examined the reactivity of [Li(2.2.2-cryptand)][ 1 ] toward norbornene and diphenylacetylene in THF- d 8 , however no reaction was observed in either case. In contrast, Dixneuf and co-workers have shown that ruthenium allenylidenes are competent precatalysts for ring-closing metathesis, enyne metathesis, and ring-opening metathesis polymerization. ,,− It is not immediately clear why [Li(2.2.2-cryptand)][ 1 ] is unreactive toward olefins and alkynes, but it may be due to the steric inaccessibility of the Th center caused by the presence of three cyclopentadienyl coligands.…”

Asymmetric Synthesis of Cyclic Fluorinated Amino Acids

“…Having in hands these aminodiene compounds, we focused our attention on the synthesis of the correspondingly substituted chiral tetrahydropyridines by a RCM protocol. Some previous works in the literature have already described RCM reactions with CF 3 ‐amines to obtain trifluoromethylated nitrogen heterocycles . Among the commercially available ruthenium‐based alkylidine Grubbs catalysts, we chose the air‐ and moisture‐stable Grubbs' second‐generation catalyst, which was widely used for the synthesis of sterically hindered poly‐substituted dienes, aminodienes, and large‐size rings.…”

Synthesis of trifluoromethyl N , N -aminals from nitrogen containing heterocycles by using a plasma flow microreactor

“…To access a-trifluoromethyl amino derivatives, [7][8][9][10][11][12][13][14][15][16][17][18] N,O-trifluoromethyl acetals A [19][20][21][22] and trifluoromethyl N,N-aminals A 023-25 are useful as the treatment of A and A 0 , under acidic conditions, led to trifluoromethyl iminium intermediates B which can be trapped by a variety of nucleophiles to produce a diversity of a-trifluoromethyl amino derivatives C (Scheme 1, eqn (1)). However, to synthesize N, N-aminals either drastic conditions 23,24 are used (Scheme 1, eqn (2)), or several steps are required to produce these compounds from amines [19][20][21][22] (Scheme 1, eqn (3)), or the use of additives is necessary 25 (Scheme 1, eqn (2)-( 4)).…”

An Actinide Complex with a Nucleophilic Allenylidene Ligand

“…We also examined the reactivity of [Li(2.2.2-cryptand)][ 1 ] toward norbornene and diphenylacetylene in THF- d 8 , however no reaction was observed in either case. In contrast, Dixneuf and co-workers have shown that ruthenium allenylidenes are competent precatalysts for ring-closing metathesis, enyne metathesis, and ring-opening metathesis polymerization. ,,− It is not immediately clear why [Li(2.2.2-cryptand)][ 1 ] is unreactive toward olefins and alkynes, but it may be due to the steric inaccessibility of the Th center caused by the presence of three cyclopentadienyl coligands.…”

Asymmetric Synthesis of Cyclic Fluorinated Amino Acids

“…Having in hands these aminodiene compounds, we focused our attention on the synthesis of the correspondingly substituted chiral tetrahydropyridines by a RCM protocol. Some previous works in the literature have already described RCM reactions with CF 3 ‐amines to obtain trifluoromethylated nitrogen heterocycles . Among the commercially available ruthenium‐based alkylidine Grubbs catalysts, we chose the air‐ and moisture‐stable Grubbs' second‐generation catalyst, which was widely used for the synthesis of sterically hindered poly‐substituted dienes, aminodienes, and large‐size rings.…”

Synthesis of trifluoromethyl N , N -aminals from nitrogen containing heterocycles by using a plasma flow microreactor

“…To access a-trifluoromethyl amino derivatives, [7][8][9][10][11][12][13][14][15][16][17][18] N,O-trifluoromethyl acetals A [19][20][21][22] and trifluoromethyl N,N-aminals A 023-25 are useful as the treatment of A and A 0 , under acidic conditions, led to trifluoromethyl iminium intermediates B which can be trapped by a variety of nucleophiles to produce a diversity of a-trifluoromethyl amino derivatives C (Scheme 1, eqn (1)). However, to synthesize N, N-aminals either drastic conditions 23,24 are used (Scheme 1, eqn (2)), or several steps are required to produce these compounds from amines [19][20][21][22] (Scheme 1, eqn (3)), or the use of additives is necessary 25 (Scheme 1, eqn (2)-( 4)).…”