141966-91-8Relevant academic research and scientific papers
Enantioselective and Diastereodivergent Synthesis of Spiroindolenines via Chiral Phosphoric Acid-Catalyzed Cycloaddition
Varlet, Thomas,Mati?i?, Mateja,Van Elslande, Elsa,Neuville, Luc,Gandon, Vincent,Masson, Géraldine
supporting information, p. 11611 - 11619 (2021/08/16)
A diastereodivergent and enantioselective synthesis of chiral spirocyclohexyl-indolenines with four contiguous stereogenic centers is achieved by a chiral phosphoric acid-catalyzed cycloaddition of 2-susbtituted 3-indolylmethanols with 1,3-dienecarbamates. Modular access to two different diastereoisomers with high enantioselectivities was obtained by careful choice of reaction conditions. Their functional group manipulation provides an efficient access to enantioenriched spirocyclohexyl-indolines and -oxindoles. The origins of this stereocontrol have been identified using DFT calculations, which reveal an unexpected mechanism compared to our previous work dealing with enecarbamates.
Highly Diastereo- and Enantioselective Synthesis of Cyclohepta[b]indoles by Chiral-Phosphoric-Acid-Catalyzed (4+3) Cycloaddition
Gelis, Coralie,Levitre, Guillaume,Merad, Jérémy,Retailleau, Pascal,Neuville, Luc,Masson, Géraldine
supporting information, p. 12121 - 12125 (2018/09/11)
A highly enantio- and diastereoselective formal (4+3) cycloaddition of 1,3-diene-1-carbamates with 3-indolylmethanols in the presence of a chiral phosphoric acid catalyst is reported. The approach described herein provides efficient access to 6-aminotetrahydrocyclohepta[b]indoles in good yields with mostly complete diastereoselectivity and excellent levels of enantioselectivity (>98:2 dr and up to 98 % ee). Mild reaction conditions, facile scale-up, and versatile derivatization highlight the practicality of this methodology. A mechanistic study suggests that cycloaddition occurs in a stepwise fashion, after the formation of an ion pair between the chiral catalytic phosphate and the intermediate carbocation.
Synthesis of indoles via 6π-electrocyclic ring closures of trienecarbamates
Greshock, Thomas J.,Funk, Raymond L.
, p. 4946 - 4947 (2007/10/03)
A new method for the preparation of indoles from readily available α-haloenones and α-(trialkylstannyl)enecarbamates is described. Following a Stille coupling, trienecarbamate 2 is electronically activated to undergo a facile 6π-electrocyclic ring closure
