Orthogonal Cu- and Pd-Based Catalyst Systems for the O- and N-Arylation of Aminophenols
摘要:
O- or N-arylated aminophenol products constitute a common structural motif in various potentially useful therapeutic agents and/or drug candidates. We have developed a complementary set of Cu- and Pd-based catalyst systems for the selective O- and N-arylation of unprotected aminophenols using aryl halides. Selective O-arylation of 3- and 4-aminophenols is achieved with copper-catalyzed methods employing picolinic acid or CyDMEDA, trans-N,N'-dimethyl-1,2-cyclohexanediamine, respectively, as the ligand. The selective formation of N-arylated products of 3- and 4-aminophenols can be obtained with BrettPhos precatalyst, a biarylmonophosphine-based palladium catalyst. 2-Aminophenol can be selectively N-arylated with CuI, although no system for the selective O-arylation could be found. Coupling partners with diverse electronic properties and a variety of functional groups can be selectively transformed under these conditions.
Copper(<scp>ii</scp>)-catalyzed Chan–Lam cross-coupling: chemoselective N-arylation of aminophenols
作者:A. Siva Reddy、K. Ranjith Reddy、D. Nageswar Rao、Chaitanya K. Jaladanki、Prasad V. Bharatam、Patrick Y. S. Lam、Parthasarathi Das
DOI:10.1039/c6ob02444k
日期:——
Copper(II)-catalyzed boronic acid promoted chemoselective N-arylation of unprotected aminophenols has been developed. Selective N-arylation of 3-aminophenol is achieved with a Cu(OAc)2/AgOAc combination in MeOH at rt, whereas the chemoselective N-arylated products of 4-aminophenol can be obtained with a Cu(OAc)2/Cs2CO3 system and benzoic acid as an additive. These ligand-free conditions and “open-flask”
Novel hydroxyphenylaminobenzenealkanols, useful as antiasthmatic agents, are of the formula
wherein R is hydrogen, lower-alkyl, lower-alkoxy or halo; R'is hydrogen or lower-alkyl; R"is hydrogen, lower-alkyl or halo; and Y is CnH2n wherein n is 1-2. The compounds are prepared by de-etherification of the corresponding phenol alkyl or benzyl ethers; by reduction of the corresponding benzoic acids or esters thereof; or by reduction of ketones wherein -Y-OH is replaced by -COCH3. The invention also relates to the novel benzyl ether intermediates.
可用作抗哮喘药的新型羟苯胺苯烷醇的结构式为
其中 R 是氢、低级烷基、低级烷氧基或卤素;R'是氢或低级烷基;R "是氢、低级烷基或卤素;Y 是 CnH2n,其中 n 是 1-2。这些化合物的制备方法有:相应的苯酚烷基醚或苄基醚的脱醚;相应的苯甲酸或其酯的还原;或酮的还原,其中 -Y-OH 被 -COCH3 取代。本发明还涉及新型苄基醚中间体。
Terdic,M., Justus Liebigs Annalen der Chemie, 1971, vol. 746, p. 200 - 206