Premium
Rh‐Catalyzed Decarbonylative Cross‐Coupling between o ‐Carboranes and Twisted Amides: A Regioselective, Additive‐Free, and Concise Late‐Stage Carboranylation
Author(s) -
Li ChunXiao,
Ning Qian,
Zhao Wenxuan,
Cao HouJi,
Wang YiPing,
Yan Hong,
Lu ChangSheng,
Liang Yong
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202003634
Subject(s) - carborane , chemistry , amide , combinatorial chemistry , imine , reagent , catalysis , boron , regioselectivity , dimer , stereochemistry , substrate (aquarium) , ligand (biochemistry) , coupling reaction , organic chemistry , biochemistry , oceanography , receptor , geology
The convenient cross‐coupling of sp 2 or sp 3 carbons with a specific boron vertex on carborane cage represents significant synthetic values and insurmountable challenges. In this work, we report an Rh‐catalyzed reaction between o ‐carborane and N ‐acyl‐glutarimides to construct various B cage −C bonds. Under the optimized condition, the removable imine directing group (DG) leads to B(3)− or B(3,6)−C couplings, while the pyridyl DG leads to B(3,5)−Ar coupling. In particular, an unexpected rearrangement of amide reagent is observed in pyridyl directed B(4)−C(sp 3 ) formation. This scalable protocol has many advantages, including easy access, the use of cheap and widely available coupling agents, no requirement of an external ligand, base or oxidant, high efficiency, and a broad substrate scope. Leveraging the Rh I dimer and twisted amides, this method enables straightforward access to diversely substituted and therapeutically important carborane derivatives at boron site, and provides a highly valuable vista for carborane‐based drug screening.