Mapping Dual‐Base‐Enabled Nickel‐Catalyzed Aryl Amidations: Application in the Synthesis of 4‐Quinolones
摘要:
AbstractThe C−N cross‐coupling of (hetero)aryl (pseudo)halides with NH substrates employing nickel catalysts and organic amine bases represents an emergent strategy for the sustainable synthesis of (hetero)anilines. However, unlike protocols that rely on photoredox/electrochemical/reductant methods within NiI/III cycles, the reaction steps that comprise a putative Ni0/II C−N cross‐coupling cycle for a thermally promoted catalyst system using organic amine base have not been elucidated. Here we disclose an efficient new nickel‐catalyzed protocol for the C−N cross‐coupling of amides and 2′‐(pseudo)halide‐substituted acetophenones, for the first time where the (pseudo)halide is chloride or sulfonate, which makes use of the commercial bisphosphine ligand PAd2‐DalPhos (L4) in combination with an organic amine base/halide scavenger, leading to 4‐quinolones. Room‐temperature stoichiometric experiments involving isolated Ni0, I, and II species support a Ni0/II pathway, where the combined action of DBU/NaTFA allows for room‐temperature amide cross‐couplings.
N-Alkylated 2-Trifluoromethyl-4-quinolones by Addition of Base and an Alkylating Agent to 2-Trifluoroacetylaminoacetophenones
摘要:
2-Trifluoroacetylaminoacetophenones 1 are cyclized to N-alkyl-2-trifluoromethyl-4-quinolones 2 in one pot with concomitant N-alkylation in 40 to 74% yield using potassium hydroxide in acetone containing an alkylating agent.
The reaction of o-amino aryl carboxylic acids with Grignard reagents. The unusual effect of the N-protecting group on aryl ketone formation
作者:Puwen Zhang、Eugene A Terefenko、Joseph Slavin
DOI:10.1016/s0040-4039(01)00160-5
日期:2001.3
The addition of Grignard reagents to the o-amino aryl carboxylic acids without any additive forms the tertiary carbinol as a major product. Unexpectedly, the aryl ketones are formed as the only isolated product if o-amino moiety of anthranilic acids is protected with Boc, trifluoroacetyl, and pivaloyl protecting groups.
(wherein R
1
and R
4
are the same or different and each represents a hydrogen atom, substituted or unsubstituted lower alkyl, substituted or unsubstituted lower alkynyl, substituted or unsubstituted lower alkenyl, or the like; R
5
represents a substituted or unsubstituted heterocyclic group, substituted or unsubstituted aryl, or the like; R
2
represents —C(═W)R
6
or the like; R
3
represents a hydrogen atom, —C(═W
A
)R
6A
, or the like)
Antitumor agents which comprises a thiadiazoline derivative represented by the aforementioned general formula (I) or a pharmacologically acceptable salt thereof as an active ingredient are provided.
(wherein R
1
and R
4
are the same or different and each represents a hydrogen atom, substituted or unsubstituted lower alkyl, substituted or unsubstituted lower alkynyl, substituted or unsubstituted lower alkenyl, or the like; R
5
represents a substituted or unsubstituted heterocyclic group, substituted or unsubstituted aryl, or the like; R
2
represents —C(═W)R
6
or the like; R
3
represents a hydrogen atom, —C(═W
A
)R
6A
, or the like)
Antitumor agents which comprises a thiadiazoline derivative represented by the aforementioned general formula (I) or a pharmacologically acceptable salt thereof as an active ingredient are provided.
A mitotic kinesin Eg5 inhibitor which comprises a thiadiazoline derivative represented by the general formula (I) or a pharmacologically acceptable salt thereof as an active ingredient:
[wherein R
1
represents a hydrogen atom and the like, R
2
represents a hydrogen atom, —C(═W)R
6
(wherein W represents an oxygen atom or a sulfur atom, and R
6
represents substituted or unsubstituted lower alkyl and the like) and the like, R
3
represents —C(═Z)R
19
(wherein Z represents an oxygen atom or a sulfur atom, and R
19
represents substituted or unsubstituted lower alkyl and the like) and the like, R
4
represents substituted or unsubstituted lower alkyl and the like, and R
5
represents substituted or unsubstituted aryl and the like] and the like are provided.