Palladium-Catalyzed, Modular Synthesis of Highly Functionalized Indoles and Tryptophans by Direct Annulation of Substituted <i>o</i>-Haloanilines and Aldehydes
作者:Yanxing Jia、Jieping Zhu
DOI:10.1021/jo061471s
日期:2006.9.1
One-pot synthesis of indoles by a palladium-catalyzed annulation of ortho-haloanilines and aldehydes has been developed. Coupling of ortho-iodoaniline with aldehyde is realized under mild ligandless conditions [Pd(OAc)2, DABCO, DMF, 85 °C], whereas X-Phos is found to be the ligand of choice for coupling reactions involving ortho-chloroanilines/ortho-bromoanilines and aldehydes. A variety of ortho-haloanilines
Synthetic studies of 3-(3-fluorooxindol-3-yl)-l-alanine
作者:Tomoya Fujiwara、Bin Yin、Meixiang Jin、Kenneth L. Kirk、Yoshio Takeuchi
DOI:10.1016/j.jfluchem.2008.06.026
日期:2008.9
Oxidative fluorination of several protected tryptophans 8b-g with Selectfluor (TM) proceeded smoothly in aqueous media to give a diastereomeric mixture of the corresponding 3-fluorooxindoles 9b-g. Attempted deprotection of the 3-fluorooxindoles 9b-g under various conditions did not afford 3-(3-fluorooxindol-3-yl)-L-alanine (6). Reaction of the suitably protected tryptophan derivative 16 with Selectfluor (TM) produced the fluorinated product 17. Simultaneous cleavage of all protective groups of 17 under acidic conditions successfully gave the target compound 6 in excellent yield. (c) 2008 Elsevier B.V. All rights reserved.
Indium-mediated facile cleavage of the t-butoxycarbonyl group from di-t-butylimidodicarbonate
Di-t-butylimidodiacarbonates are selectively and efficiently deprotected to the corresponding mono-BOC protected amines in high yields using indium or zinc metal in refluxing methanol. Simple BOC and CBz protected amines are unaffected by these conditions. (C) 2002 Elsevier Science Ltd. All rights reserved.