1258238-88-8Relevant articles and documents
Refining boron-iodane exchange to access versatile arylation reagents
Karandikar, Shubhendu S.,Stuart, David R.
supporting information, p. 1211 - 1214 (2022/02/03)
Aryl(Mes)iodonium salts, which are multifaceted aryl transfer reagents, are synthesized via boron-iodane exchange. Modification to both the nucleophilic (aryl boron) and electrophilic (mesityl-λ3-iodane) reaction components results in improved yield and faster reaction time compared to previous conditions. Mechanistic studies reveal a pathway that is more like transmetallation than SEAr.
Scope of the palladium-catalyzed aryl borylation utilizing bis-boronic acid
Molander, Gary A.,Trice, Sarah L. J.,Kennedy, Steven M.,Dreher, Spencer D.,Tudge, Matthew T.
, p. 11667 - 11673 (2012/09/05)
The Suzuki-Miyaura reaction has become one of the more useful tools for synthetic organic chemists. Until recently, there did not exist a direct way to make the most important component in the coupling reaction, namely the boronic acid. Current methods to make boronic acids often employ harsh or wasteful reagents to prepare boronic acid derivatives and require additional steps to afford the desired boronic acid. The scope of the previously reported palladium-catalyzed, direct boronic acid synthesis is unveiled, which includes a wide array of synthetically useful aryl electrophiles. It makes use of the newly available second generation Buchwald XPhos preformed palladium catalyst and bis-boronic acid. For ease of isolation and to preserve the often sensitive C-B bond, all boronic acids were readily converted to their more stable trifluoroborate counterparts.
Palladium-catalyzed borylation of aryl and heteroaryl halides utilizing tetrakis(dimethylamino)diboron: One step greener
Molander, Gary A.,Trice, Sarah L. J.,Kennedy, Steven M.
, p. 4814 - 4817,4 (2012/12/12)
The palladium-catalyzed borylation of aryl and heteroaryl halides with a novel borylating agent, tetrakis(dimethylamino)diboron [(Me2N) 2B-B(NMe2)2], is reported. The method is complementary to the previously reported method utilizing bis-boronic acid (BBA) in that certain substrates perform better under one set of optimized reaction conditions than the other. Because tetrakis(dimethylamino)diboron is the synthetic precursor to both BBA and bis(pinacolato)diboron (B 2Pin2), the new method represents a more atom-economical and efficient approach to current borylation methods.
Palladium-catalyzed, direct boronic acid synthesis from aryl chlorides: A simplified route to diverse boronate ester derivatives
Molander, Gary A.,Trice, Sarah L. J.,Dreher, Spencer D.
, p. 17701 - 17703 (2011/03/16)
Although much current research focuses on developing new boron reagents and identifying robust catalytic systems for the cross-coupling of these reagents, the fundamental preparations of the nucleophilic partners (i.e., boronic acids and derivatives) has been studied to a lesser extent. Most current methods to access boronic acids are indirect and require harsh conditions or expensive reagents. A simple and efficient palladium-catalyzed, direct synthesis of arylboronic acids from the corresponding aryl chlorides using an underutilized reagent, tetrahydroxydiboron B2(OH)4, is reported. To ensure preservation of the carbon-boron bond, the boronic acids were efficiently converted to the trifluoroborate derivatives in good to excellent yields without the use of a workup or isolation. Further, the intermediate boronic acids can be easily converted to a wide range of useful boronates. Finally, a two-step, one-pot method was developed to couple two aryl chlorides efficiently in a Suzuki-Miyaura-type reaction.
