TY - JOUR
T1 - Synthesis and Catalytic Applications of a Triptycene-Based Monophosphine Ligand for Palladium-Mediated Organic Transformations
AU - Leung, Franco King Chi
AU - Ishiwari, Fumitaka
AU - Shoji, Yoshiaki
AU - Nishikawa, Tsuyoshi
AU - Takeda, Ryohei
AU - Nagata, Yuuya
AU - Suginome, Michinori
AU - Uozumi, Yasuhiro
AU - Yamada, Yoichi M.A.
AU - Fukushima, Takanori
N1 - Funding Information:
This work was partially supported by a Grant-in-Aid for Scientific Research on Innovative Areas “π-Figuration” (no. 26102008 for T.F., no. 15H00994 for Y.N.) and “Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials” from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT). F.K.C.L. kindly acknowledges the International Program Associate (IPA) of RIKEN. We thank K. Osakada and D. Takeuchi (Tokyo Institute of Technology) for their support with the specific optical rotation measurement. We thank Suzukakedai Materials Analysis Division, Technical Department, Tokyo Institute of Technology, for their support with the NMR measurement.
Publisher Copyright:
© 2017 American Chemical Society.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2017/5/31
Y1 - 2017/5/31
N2 - 1-Methoxy-8-(diphenylphosphino)triptycene (1), featuring high structural rigidity and steric bulkiness around the phosphine functionality, was synthesized as a new chiral monophosphine ligand for transition metal-catalyzed reactions. In the presence of 5-10 mol ppm (i.e., 0.0005-0.001 mol %) Pd(OAc)2 and 1 (2 equiv for Pd), Suzuki-Miyaura cross-coupling reactions of aryl bromides and arylboronic acids proceeded effectively under mild atmospheric conditions to give the corresponding biaryl compounds in a high yield. The single-crystal X-ray analysis of a Pd(II) complex of 1 revealed its coordination structure, in which two homochiral molecules form a dimer, suggesting that triptycene could provide a chiral environment for asymmetric organic transformations. In fact, optically active 1 obtained by optical resolution showed good enantioselectivity in the palladium-catalyzed asymmetric hydrosilylation of styrene, which represents, for the first time, the asymmetric catalytic activity of triptycene-based monophosphine ligands.
AB - 1-Methoxy-8-(diphenylphosphino)triptycene (1), featuring high structural rigidity and steric bulkiness around the phosphine functionality, was synthesized as a new chiral monophosphine ligand for transition metal-catalyzed reactions. In the presence of 5-10 mol ppm (i.e., 0.0005-0.001 mol %) Pd(OAc)2 and 1 (2 equiv for Pd), Suzuki-Miyaura cross-coupling reactions of aryl bromides and arylboronic acids proceeded effectively under mild atmospheric conditions to give the corresponding biaryl compounds in a high yield. The single-crystal X-ray analysis of a Pd(II) complex of 1 revealed its coordination structure, in which two homochiral molecules form a dimer, suggesting that triptycene could provide a chiral environment for asymmetric organic transformations. In fact, optically active 1 obtained by optical resolution showed good enantioselectivity in the palladium-catalyzed asymmetric hydrosilylation of styrene, which represents, for the first time, the asymmetric catalytic activity of triptycene-based monophosphine ligands.
UR - http://www.scopus.com/inward/record.url?scp=85028958323&partnerID=8YFLogxK
U2 - 10.1021/acsomega.7b00200
DO - 10.1021/acsomega.7b00200
M3 - Journal article
AN - SCOPUS:85028958323
SN - 2470-1343
VL - 2
SP - 1930
EP - 1937
JO - ACS Omega
JF - ACS Omega
IS - 5
ER -