Helvetica Chimica Acta p. 799 - 852 (2013)
Update date:2022-08-15
Topics:
Seebach, Dieter
Sun, Xiaoyu
Ebert, Marc-Olivier
Schweizer, W. Bernd
Purkayastha, Nirupam
Beck, Albert K.
Duschmale, Joerg
Wennemers, Helma
Mukaiyama, Takasuke
Benohoud, Meryem
Hayashi, Yujiro
Reiher, Markus
The stoichiometric reactions of enamines prepared from aldehydes and diphenyl-prolinol silyl ethers (intermediates of numerous organocatalytic processes) with nitro olefins have been investigated. As reported in the last century for simple achiral and chiral enamines, the products are cyclobutanes (4 with monosubstituted nitro-ethenes), dihydro-oxazine N-oxide derivatives (5 with disubstituted nitro-ethenes), and nitro enamines derived from γ-nitro aldehydes (6, often formed after longer reaction times). The same types of products were shown to be formed, when the reactions were carried out with peptides H-Pro-Pro-Xaa-OMe that lack an acidic H-atom. Functionalized components such as alkoxy enamines, nitro-acrylates, acetamido-nitro-ethylene, or hydroxylated nitro olefins also form products carrying the diphenyl-prolinol silyl ether as a substituent. All of these products must be considered intermediates in the corresponding catalytic reactions; the investigation of their chemical properties provided useful hints about the rates, the conditions, the catalyst resting states or irreversible traps, and/or the limitations of the corresponding organocatalytic processes. High-level DFT and MP2 computations of the structures of alkoxy enamines and thermodynamic data of a cyclobutane dissociation are also described. Some results obtained with the stoichiometrically prepared intermediates are not compatible with previous mechanistic proposals and assumptions. Copyright
View MoreAnhui Asahikasei Chemical Co., Ltd
Contact:86-551-4259770
Address:No. 88 Linquan Road Hefei Anhui China
Shanghai Sunwise Chemical Co., Ltd
website:http://www.sunwisechem.com
Contact:86-021-33883180
Address:Room 10E, Building G, Westlink Center, No. 2337 Gudai Road, Minhang District, Shanghai, China PC: 201100
NanJing Rate Biochemicals CO., LTD
Contact:+86-25-84931986
Address:NO. 1 Hongjing Road,Jiangning Science Park,Nanjing,China
Suzhou CarbonWell Pharma-Tech Co., Ltd
Contact:Tel: + 86 (0)512-8898-1216; + 86-18606258602
Address:2358 Changan Road, Wujiang Scientific Innovation Park, Wujiang, Jiangsu Province, P. R. China 215200
Shanghai AoBo Bio-Pharmaceutical Technology Co., Ltd.
Contact:+86-21-51320130-801, 816
Address:Room 601, No. 1011, Halei Road, Zhangjiang High-Tech Park, Pudong, Shanghai
Doi:10.1016/0040-4039(92)88128-R
(1992)Doi:10.1002/chem.201302699
(2014)Doi:10.1016/0020-1693(95)04618-J
(1995)Doi:10.1080/10242422.2017.1352585
(2017)Doi:10.1016/j.tetlet.2012.10.062
(2012)Doi:10.1002/jhet.1580
(2014)