A mild and simple procedure for the reductive cleavage of acetals and ketals
作者:Adusumilli Srikrishna、Ranganathan Viswajanani
DOI:10.1016/0040-4020(95)00055-d
日期:1995.3
A convenient, mild and simple procedure, employing sodium cyanoborohydride in the presence of either catalytic or stoichiometric amount of boron trifluoride etherate in dry THF, for the reductive cleavage of the acetals and ketals is described.
A compound represented by the general formula (I):
wherein R
1
is a hydrogen atom, a halogen atom, or the like; R
2
, R
3
, and R
4
are each independently a hydrogen atom, a halogen atom, C1-C15 alkyl optionally substituted with one or more C1-C12 alkyloxy or the like, or the like; R
5
is a hydrogen atom or the like; R
6
and R
7
are a hydrogen atom or the like; R
8
is C1-C3 alkyl or the like; R
9
is a hydrogen atom or the like), a prodrug, a pharmaceutically acceptable salt, or solvate thereof.
A compound represented by the general formula (I):
wherein R
1
is a hydrogen atom, a halogen atom, or the like; R
2
, R
3
, and R
4
are each independently a hydrogen atom, a halogen atom, C1-C15 alkyl optionally substituted with one or more C1-C12 alkyloxy or the like, or the like; R
5
is a hydrogen atom or the like; R
6
and R
7
are a hydrogen atom or the like; R
8
is C1-C3 alkyl or the like; R
9
is a hydrogen atom or the like), a prodrug, a pharmaceutically acceptable salt, or solvate thereof.
High yields of aromatic, aromatic acetic and olefinic acids, esters, amides and the like are derived from a process wherein a halo-hydrocarbon is carbonylated in the presence of a palladium catalyst, a hindered amine base and phosphine in excess. The hindered amine base can comprise C₃-C₁₀ branched alkyls, cyclic compounds, or mixtures of the above. The preferred amine is N,N-diisopropylethyl amine. The preferred catalyst is PdCl₂(PPH₃)₂ with the excess phosphine generally supplied by a compound of the formula PR¹R²R³ where R¹,R² and R³ are preferably phenyl.
Single phase carbonylation of aromatic halides to carboxylic acid salts
申请人:STAUFFER CHEMICAL COMPANY
公开号:EP0273553A1
公开(公告)日:1988-07-06
A process for preparing carboxylic acid salts by the reaction of carbon monoxide with substituted or unsubstituted aromatic halides or an aliphatic organic halide comprises the catalyst single phase carbonylation of the halide utilizing in addition to carbon monoxide, a palladium catalyst, an excess of tertiary phosphine, optionally an amine compound, with an alkali metal or alkaline earth metal base added during the reaction to form the salt.