TY - JOUR
T1 - All Non-Carbon B 3 NO 2 Exotic Heterocycles
T2 - Synthesis, Dynamics, and Catalysis
AU - Opie, Christopher R.
AU - Noda, Hidetoshi
AU - Shibasaki, Masakatsu
AU - Kumagai, Naoya
N1 - Funding Information:
This work was financially supported by KAKENHI (17H03025 and 18H04276 in Precisely Designed Catalysts with Customized Scaffolding) from JSPS and MEXT. N.K. thanks the Shorai Foundation for financial support. Dr. Tomoyuki Kimura is gratefully acknowledged for the X-ray crystallographic analysis of 5e. We are grateful to Dr. Ryuichi Sawa, Ms. Yumiko Kubota, Dr. Kiyoko Iijima, and Ms. Yuko Takahashi for the NMR and HRMS analysis.
Funding Information:
This work was financially supported by KAKENHI (17H03025 and 18H04276 in Precisely Designed Catalysts with Customized Scaffolding) from JSPS and MEXT. N.K. thanks the Shorai Foundation for financial support. Dr. Tomoyuki Kimura is gratefully acknowledged for the X-ray crystallographic analysis of 5 e. We are grateful to Dr. Ryuichi Sawa, Ms. Yumiko Kubota, Dr. Kiyoko Iijima, and Ms. Yuko Takahashi for the NMR and HRMS analysis.
Publisher Copyright:
© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/3/27
Y1 - 2019/3/27
N2 - The B 3 NO 2 six-membered heterocycle (1,3-dioxa-5-aza-2,4,6-triborinane=DATB), comprising three different non-carbon period 2 elements, has been recently demonstrated to be a powerful catalyst for dehydrative condensation of carboxylic acids and amines. The tedious synthesis of DATB, however, has significantly diminished its utility as a catalyst, and thus the inherent chemical properties of the ring system have remained virtually unexplored. Here, a general and facile synthetic strategy that harnesses a pyrimidine-containing scaffold for the reliable installation of boron atoms is disclosed, giving rise to a series of Pym-DATBs from inexpensive materials in a modular fashion. The identification of a soluble Pym-DATB derivative allowed for the investigation of the dynamic nature of the B 3 NO 2 ring system, revealing differential ring-closing and -opening behaviors depending on the medium. Readily accessible Pym-DATBs proved their utility as efficient catalysts for dehydrative amidation with broad substrate scope and functional-group tolerance, offering a general and practical catalytic alternative to reagent-driven amidation.
AB - The B 3 NO 2 six-membered heterocycle (1,3-dioxa-5-aza-2,4,6-triborinane=DATB), comprising three different non-carbon period 2 elements, has been recently demonstrated to be a powerful catalyst for dehydrative condensation of carboxylic acids and amines. The tedious synthesis of DATB, however, has significantly diminished its utility as a catalyst, and thus the inherent chemical properties of the ring system have remained virtually unexplored. Here, a general and facile synthetic strategy that harnesses a pyrimidine-containing scaffold for the reliable installation of boron atoms is disclosed, giving rise to a series of Pym-DATBs from inexpensive materials in a modular fashion. The identification of a soluble Pym-DATB derivative allowed for the investigation of the dynamic nature of the B 3 NO 2 ring system, revealing differential ring-closing and -opening behaviors depending on the medium. Readily accessible Pym-DATBs proved their utility as efficient catalysts for dehydrative amidation with broad substrate scope and functional-group tolerance, offering a general and practical catalytic alternative to reagent-driven amidation.
KW - amidation
KW - boron
KW - catalysis
KW - heterocycles
KW - triborinane
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U2 - 10.1002/chem.201900715
DO - 10.1002/chem.201900715
M3 - Article
C2 - 30770614
AN - SCOPUS:85062769834
VL - 25
SP - 4648
EP - 4653
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 18
ER -