Regioselective Halogenation of Arenes and Heterocycles in Hexafluoroisopropanol
作者:Ren-Jin Tang、Thierry Milcent、Benoit Crousse
DOI:10.1021/acs.joc.7b02920
日期:2018.1.19
halogenation of arenes and heterocycles with N-halosuccinimides in fluorinated alcohols is disclosed. Under mild condition reactions, a wide diversity of halogenated arenes are obtained in good yields with high regioselectivity. Additionally, the versatility of the method is demonstrated by the development of one-pot sequential halogenation and halogenation-Suzuki cross-couplingreactions.
A Green Protocol for the Bromination and Iodination of the Aromatic Compounds using H<sub>5</sub>IO<sub>6</sub>/NaBr and H<sub>5</sub>IO<sub>6</sub>/NaI in the Water
作者:Jaber Yousefi-Seyf、Kazem Tajeian、Eskandar Kolvari、Nadiya Koukabi、Ardeshir Khazaei、Mohammad Ali Zolfigol
DOI:10.5012/bkcs.2012.33.8.2619
日期:2012.8.20
C, respectively, in short reaction times using orthoperiodic acid/sodium bromide (1:2) andorthoperiodic acid/sodium iodide (1:2) in water to prepare the corresponding halo compounds with excellentyields.Key Words : Iodination, Bromination, Orthoperiodic acid, WaterIntroductionOrganic halides are an important class of intermediates asthey can be converted efficiently into other functionalgroups by simple
Synthesis of<i>C</i><sub>2</sub>-Symmetric Bisphosphine Ligands from Tartaric Acid, and Their Performance in the Pd-Catalyzed Asymmetric<i>O</i>-Allylation of a Phenol
Starting fromtartaricacid derived chiral diols or dicarboxylic acid dichlorides with either a 2,2-dimethyl-1,3-dioxolane (Taddol) or a 2,3-dimethoxy-2,3-dimethyl-1,4-dioxane (Tatrol) core structure, and BH3-protected ortho-phosphanyl phenols, a set of fourteen new C2-symmetric diphosphine ligands was synthesized. In addition, three related ligands were obtained from ortho-diphenylphosphino-anilines
The Catalyst-Controlled Regiodivergent Chlorination of Phenols
作者:Sean M. Maddox、Andrew N. Dinh、Felipe Armenta、Joann Um、Jeffrey L. Gustafson
DOI:10.1021/acs.orglett.6b02650
日期:2016.11.4
overcome the innate para-selectivity of electrophilic phenolchlorination, yielding ortho-chlorinated phenols that are not readily obtainable via canonical electrophilic chlorinations. Conversely, a phosphine sulfide derived from 2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) was found to enhance the innate para-preference of phenolchlorination.
The AuI‐catalyzed reaction of 2‐(1‐alkynyl)‐2‐alken‐1‐ones with azomethine imines regio‐ and diastereoselectively affords furo[3,4‐d]tetrahydropyridazines in a tandem cyclization/intermolecular [3+3]‐cycloaddition process under mild conditions. By employing a chiral gold catalyst (prepared in situ from a Taddol‐derived phosphine‐phosphite ligand, Me2SAuCl, and AgOTf) high yields and enantioselectivities