Mild Debenzylation of Aryl
Benzyl Ether with BCl3 in the Presence of Pentamethylbenzene
as a Non-Lewis-Basic Cation Scavenger
摘要:
Scope and limitations of the debenzylation conditions for aryl benzyl ether, which was developed during our synthetic studies on yatakemycin, were investigated. The chemoselective debenzylation proceeds at low temperature with a combination of BCl(3) and pentamethylbenzene as a cation scavenger in the presence of various functional groups.
Synthesis of Flavanones via Palladium(II)-Catalyzed One-Pot β-Arylation of Chromanones with Arylboronic Acids
作者:Hyung-Seok Yoo、Seung Hwan Son、Yang Yil Cho、Soo Jin Lee、Hyu Jeong Jang、Young Min Kim、Dong Hwan Kim、Nam Yong Kim、Boyoung Y. Park、Yong Sup Lee、Nam-Jung Kim
DOI:10.1021/acs.joc.9b01162
日期:2019.8.16
total of 47 flavanones were expediently synthesized via one-pot β-arylation of chromanones, a class of simple ketones possessing chemically unactivated β sites, with arylboronic acids via tandem palladium(II) catalysis. This reaction provides a novel route to various flavanones, including natural products such as naringenin trimethyl ether, in yields up to 92%.
Gold(I)-Catalyzed Intramolecular Hydroarylation of Phenol-Derived Propiolates and Certain Related Ethers as a Route to Selectively Functionalized Coumarins and 2<i>H</i>-Chromenes
作者:Aymeric Cervi、Yen Vo、Christina L. L. Chai、Martin G. Banwell、Ping Lan、Anthony C. Willis
DOI:10.1021/acs.joc.0c02011
日期:2021.1.1
Methods are reported for the efficient assembly of a series of phenol-derived propiolates, including the parent system 56, and their Au(I)-catalyzed cyclization (intramolecular hydroarylation) to give the corresponding coumarins (e.g., 1). Simple syntheses of naturalproducts such as ayapin (144) and scoparone (145) have been realized by such means, and the first of these subject to single-crystal
Organozinc-mediated direct cross-coupling under microwave irradiation
作者:Chun-Jing Li
DOI:10.1177/17475198211026479
日期:2021.9
direct cross-coupling reaction between (het)aryl pivalates/tosylates and di(het)arylzinc species in 2-methyltetrahydrofuran/N-methyl pyrrolidone (1:1), which occurs via C–O bond cleavage undermicrowaveirradiation. The reaction takes place smoothly in short reaction times without the addition of any catalyst or ligand. The reaction is suitable for a broad scope of substrates and exhibits good functional
Their properties are intimately linked to the relative substitution pattern of the aromaticring, reflecting well-known electronic effects of the OH group. Because of these ortho-, para-directing effects, meta-substituted phenols have historically been more difficult to synthesize. Here we describe a procedure to transpose phenols that hinges on a regioselective diazotization of the corresponding ortho-quinone
Ni-Catalyzed Direct Reductive Amidation via C–O Bond Cleavage
作者:Arkaitz Correa、Ruben Martin
DOI:10.1021/ja5029793
日期:2014.5.21
A novel Ni-catalyzed reductive amidation of C(sp(2))-O and C(sp(3))-O electrophiles with isocyanates is described. This umpolung reaction allows for an unconventional preparation of benzamides using simple starting materials and easy-to-handle Ni catalysts.