for the preparation of 3-substituted isocoumarins via palladium-catalyzed nucleophilic addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective nucleophilic addition and C–H functionalization procedure.
Sulfoxonium Ylides as Carbene Precursors: Rhodium(III)‐Catalyzed Sequential C−H Functionalization, Selective Enol Oxygen‐Atom Nucleophilic Addition, and Hydrolysis
作者:Yuanqiong Huang、Xueli Lyu、Hongjian Song、Qingmin Wang
DOI:10.1002/adsc.201900861
日期:2019.11.19
Herein, we report a protocol for Rh(III)‐catalyzed annulation reactions between oxazolines and sulfoxonium ylides via a sequence involving C−H activation, selective enol oxygen‐atom nucleophilic addition, and hydrolysis. This practical, operationally simple protocol has a wide substrate range, excellent regioselectivity, and moderate to good yields.
Pd-Catalyzed/Iodide-Promoted α-Arylation of Ketones for the Regioselective Synthesis of Isocoumarins
作者:Alessandra Casnati、Raimondo Maggi、Giovanni Maestri、Nicola Della Ca’、Elena Motti
DOI:10.1021/acs.joc.7b01355
日期:2017.8.4
synthesized directly from 2-halobenzoates and ketones through a palladium-catalyzed α-arylation step followed by an intramolecular cyclization process. The addition of iodide anions to the reaction mixture increased yields and selectivities especially when 2-bromobenzoates were employed. This phosphine-free one-potsynthesis features a high functional group tolerance and gives access to richly decorated
Assembly of 3-Substituted Isocoumarins via a CuI-Catalyzed Domino Coupling/Addition/Deacylation Process
作者:Shangjun Cai、Fei Wang、Chanjuan Xi
DOI:10.1021/jo2026433
日期:2012.3.2
An efficient strategy for the synthesis of a variety of 3-substitutedisocoumarins has been developed. The reaction proceeded from o-halobenzoic acids and 1,3-diketones via a copper(I)-catalyzed domino reaction in DMF under the action of K3PO4 at 90–120 °C without a ligand to afford the corresponding 3-substitutedisocoumarin derivatives in good to excellent yields. o-Halobenzoic acids could be o-iodobenzoic
已经开发了用于合成多种3-取代的异香豆素的有效策略。该反应由邻卤代苯甲酸和1,3-二酮经DMF中的铜(I)催化的多米诺反应,在K 3 PO 4的作用下于90-120°C下进行,没有配体,得到相应的3-取代的异香豆素衍生物的收率为好至极好。邻卤代苯甲酸可以是邻碘苯甲酸,邻溴苯甲酸和邻氯苯甲酸衍生物。1,3-二酮可以是烷基和芳基取代的1,3-二酮。
NHC-Catalyzed Oxidative Cyclization Reactions of 2-Alkynylbenzaldehydes under Aerobic Conditions: Synthesis of O-Heterocycles
作者:Jong Hyub Park、Sachin V. Bhilare、So Won Youn
DOI:10.1021/ol200481u
日期:2011.5.6
An NHC-catalyzed, regio- and stereoselective oxidative cyclization of o-alkynylbenzaldehydes bearing an unactivated alkyne moiety as an internalelectrophile has been developed to afford phthalides and isocoumarins. A single organocatalytic system enabled two sequential C−O bond formations to take place in an atom economical manner via highly efficient dual activation. Molecular oxygen in air could