Journal of Organic Chemistry p. 6511 - 6527 (2017)
Update date:2022-08-03
Topics:
Manchala, Narasimhulu
Law, Hanson Y. L.
Kerr, Daniel J.
Volpe, Rohan
Lepage, Romain J.
White, Jonathan M.
Krenske, Elizabeth H.
Flynn, Bernard L.
Achieving ready-enantioselective access to multistereocenter-containing cyclopentyl rings is an area of great significance to organic synthesis. In this work, we describe a general protocol for accessing multistereocenter-containing cyclopentanoids from simple N-alkynyloxazolidinones (Ox-ynamides). This protocol involves conversion of Ox-ynamides into Ox-activated divinyl and aryl vinyl ketones that undergo facile Nazarov cyclization with excellent chemo-, regio-, and stereocontrol. The Ox auxiliary directs all aspects of reactivity and selectivity, both in the electrocyclization and in the subsequent transformations of the resulting oxyallyl intermediate. Stereoinduction in the electrocyclization results from a "coupled-torque" mechanism in which rotation of the Ox group, driven by increasing orbital overlap of the nitrogen lone pair with the incipient oxyallyl cation, is coupled with the rotation of the termini of the pentadienyl cation, favoring a particular direction of conrotatory ring closure (torquoselectivity). The associated lone-pair stabilization of the transition state by Ox promotes cyclization of traditionally resistant substrates, broadening the scope of this asymmetric Nazarov cyclization. The Ox group also facilitates the stereo- and regioselective incorporation of nucleophiles (Nu) and dienes, giving more complex, multistereocenter containing cyclopentanoids. Finally, the Ox group is readily removed and recovered or can be converted into other amine functionalities.
View MoreContact:021-36356756
Address:Room601,Building No.14,280 Yangcheng Road,Shanghai
ANHUI CHEM-BRIGHT BIOENGINEERING CO.,LTD
Contact:86-561-4080321
Address:No.8 Lieshan Industrial Zone of Huaibei
website:http://www.herbpurify.com
Contact:0086-028-85249238
Address:Room709-C1,Incubator Building, Tianfu Life Science Park No.88,Keyuan Road,Gaoxin district,Chengdu City,Sichuan Prov,China
Jinan Hongfangde Pharmatech Co.LTD
Contact:0531-88870908
Address:F Bldg,750#,Shunhua Rd,New&High-tech Zone,Jinan,Shandong,China 250101
Contact:86-21-50966856
Address:Building 5,300 Chuanzhan Road,Pudong New District,Shanghai
Doi:10.1016/S0022-328X(00)84705-1
(1967)Doi:10.1007/s00044-012-0025-y
(2013)Doi:10.1002/ejoc.201101601
(2012)Doi:10.1007/s10593-016-1841-7
(2016)Doi:10.1002/anie.201106710
(2012)Doi:10.1021/ja405814f
(2013)