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An Improved Synthesis of BrettPhos‐ and RockPhos‐Type Biarylphosphine Ligands
Author(s) -
Hoshiya Naoyuki,
Buchwald Stephen L.
Publication year - 2012
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/adsc.201200398
Subject(s) - chemistry , reagent , phosphine , copper , combinatorial chemistry , yield (engineering) , catalysis , stoichiometry , biphenyl , butyllithium , organic chemistry , materials science , metallurgy
Improved processes for the preparation of biphenyl‐based phosphine ligands t‐ BuBrettPhos, RockPhos, and BrettPhos are presented. The new methods, featuring the use of Grignard reagents and catalytic amounts of copper, are superior to the previous methods, which require the use of tert ‐butyllithium and stoichiometric amounts of copper. Specifically, the use of less dangerous reagents provides a safer process, while the use of catalytic amounts of copper allows for the isolation of pure products in high yield. These improvements are particularly significant for the large‐scale preparation of these ligands.