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1.
Yixiu Ge Jie Zhang Zaozao Qiu Zuowei Xie 《Angewandte Chemie (International ed. in English)》2020,59(12):4851-4855
A palladium‐catalyzed highly selective 3,4‐bifunctionalization of 3‐I‐o‐carborane has been developed, leading to the preparation of 3‐alkenyl‐4‐R‐o‐carboranes (R=alkyl, alkynyl, aryl, allyl, CN, and amido) in high to excellent yields. This protocol combines the sequential activation of cage B(3)?I and B(4)?H bonds by Pd migration from exo‐alkenyl sp2 C to cage B(4), which is driven by thermodynamic force. This represents a brand‐new strategy for selective bifunctionalization of carboranes with two different substituents. 相似文献
2.
Da Zhao Jiji Zhang Prof. Dr. Zuowei Xie 《Angewandte Chemie (International ed. in English)》2014,53(32):8488-8491
Like the importance of benzyne, witnessed in modern arene chemistry for decades, 1,2‐dehydro‐o‐carborane (o‐carboryne), a three‐dimensional relative of benzyne, has been used as a synthon for generating a wide range of cage, carbon‐functionalized carboranes over the past 20 years. However, the selective B functionalization of the cage still represents a challenging task. Disclosed herein is the first example of 1,3‐dehydro‐o‐carborane featuring a cage C? B bond having multiple bonding characters, and is successfully generated by treatment of 3‐diazonium‐o‐carborane tetrafluoroborate with non‐nucleophilic bases. This presents a new methodology for simultaneous functionalization of both cage carbon and boron vertices. 相似文献
3.
Rhodium‐Catalyzed Regioselective Hydroxylation of Cage B−H Bonds of o‐Carboranes with O2 or Air
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Hairong Lyu Dr. Yangjian Quan Prof. Dr. Zuowei Xie 《Angewandte Chemie (International ed. in English)》2016,55(39):11840-11844
A rhodium‐catalyzed hydroxylation of a cage B4?H bond in o‐carboranes with either O2 or air as the oxygen source is described, and serves as a new methodology for the regioselective generation of a series of 4‐OH‐o‐carboranes in a one‐pot process. The use of either O2 or air as both the oxidant and the oxygen source makes this protocol very environmentally friendly and practical. 相似文献
4.
Palladium‐Catalyzed Regioselective Diarylation of o‐Carboranes By Direct Cage B−H Activation
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Dr. Yangjian Quan Prof. Dr. Zuowei Xie 《Angewandte Chemie (International ed. in English)》2016,55(4):1295-1298
Palladium‐catalyzed intermolecular coupling of o‐carborane with aromatics by direct cage B?H bond activation has been achieved, leading to the synthesis of a series of cage B(4,5)‐diarylated‐o‐carboranes in high yields with excellent regioselectivity. Traceless directing group ‐COOH plays a crucial role for site‐ and di‐selectivity of such intermolecular coupling reaction. A PdII–PdIV–PdII catalytic cycle is proposed to be responsible for the stepwise arylation. 相似文献
5.
Nickel‐Catalyzed Cross‐Coupling Reactions of o‐Carboranyl with Aryl Iodides: Facile Synthesis of 1‐Aryl‐o‐Carboranes and 1,2‐Diaryl‐o‐Carboranes
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Cen Tang Prof. Dr. Zuowei Xie 《Angewandte Chemie (International ed. in English)》2015,54(26):7662-7665
A nickel‐catalyzed arylation at the carbon center of o‐carborane cages has been developed, thus leading to the preparation of a series of 1‐aryl‐o‐carboranes and 1,2‐diaryl‐o‐carboranes in high yields upon isolation. This method represents the first example of transition metal catalyzed C,C′‐diarylation by cross‐coupling reactions of o‐carboranyl with aryl iodides. 相似文献
6.
Hairong Lyu Yangjian Quan Zuowei Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(36):10769-10772
Palladium‐catalyzed direct dialkenylation of cage B(4,5) H bonds in o‐carboranes has been achieved with the help of a carboxylic acid directing group, leading to the preparation of a series of 4,5‐[trans‐(ArCHCH)]2‐ocarboranes in high yields with excellent regioselectivity. The traceless directing group, eliminated during the course of the reaction, is responsible for controlling regioselectivity and dialkenylation. A possible catalytic cycle is proposed, involving a tandem sequence of PdII‐initiated cage B H activation, alkene insertion, β‐H elimination, reductive elimination, and decarboxylation. 相似文献
7.
Dr. Yasuhiro Morisaki Masato Tominaga Takuya Ochiai Prof. Dr. Yoshiki Chujo 《化学:亚洲杂志》2014,9(5):1247-1251
The synthesis and properties of biphenyl‐ and p‐terphenyl‐fused o‐carboranes are described. Aryl rings in the biphenyl and p‐terphenyl skeletons are highly coplanar because of the presence of the o‐carborane unit. o‐Carborane exhibits an electron‐withdrawing character via the inductive effect, resulting in a decrease in both the HOMO and LUMO levels of oligophenyls without causing electronic perturbation. 相似文献
8.
Junxia Li Ronglin Pang Zhifang Li Guoqiao Lai Xu‐Qiong Xiao Thomas Müller 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(5):1411-1415
The synthesis of a series of 1,2‐diamino‐o‐carboranes ( 1 – 4 ) is reported. The molecular structures of these diamino‐o‐carboranes are remarkable as the inner‐cluster C?C bonds are all ultra‐long (162.7–193.1 pm) and vary substantially with small variations in the substituents. The results of quantum mechanical investigations suggest that the origin of the bond elongation is significant in‐plane negative hyperconjugation of lone pairs of the nitrogen substituents with the σ* orbitals of the C?C bonds in o‐carboranes. 相似文献
9.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(30):8768-8772
Direct nucleophilic substitution reaction of cage B−H bonds of o ‐carboranes by Grignard reagents in the absence of any transition metals has been achieved for the first time, and leads to the regioselective synthesis of a series of 4‐alkyl‐1,2‐diaryl‐o ‐carboranes in very high yields. The presence of two electron‐withdrawing aryl groups on the cage carbon atoms is crucial to realizing the reaction. The regioselectivity is controlled by both electronic and steric factors. This work represents a new strategy for the development of methods for carborane functionalization. 相似文献
10.
Vincent Terrasson Dr. José Giner Planas Dr. Damien Prim Prof. Francesc Teixidor Prof. Dr. Clara Viñas Prof. Dr. Mark E. Light Dr. Michael B. Hursthouse Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(44):12030-12042
The convenient synthesis of original aminobenzyl‐o‐carboranes, which represent a new class of nitrogenated carborane derivatives, is described. These novel compounds have been efficiently prepared starting from commercially available aromatic aldehydes and monosubstituted o‐carboranes via carboranyl alcohols and chlorides as intermediates. The key step of this methodology is a selective nucleophilic amination under mild conditions that allows the formation of the expected amines while limiting the partial deboronation of the carborane cluster. This general strategy has been applied to the preparation of a wide variety of aminobenzyl‐o‐carboranes. The extension of this pathway to the synthesis of enantiopure carborane–amine combinations is also described. 相似文献
11.
《中国化学》2018,36(4):273-279
o‐Carboryne (1,2‐dehydro‐o‐carborane) is a very useful synthon for the synthesis of a variety of carborane‐functionalized molecules. Diels‐Alder reaction of o‐carboryne with furans gave a series of carborane‐fused oxanorbornenes in moderate to high yields using 1‐OTf‐1,2‐C2B10H11 as carboryne precursor. The resultant cycloadducts can undergo hydrogenation, cyclic oxidation, bromination, [4 + 2]/[2 + 2] cycloaddition and nucleophilic ring opening reaction to afford a variety of highly functionalized carboranes that may find applications as useful basic units in medicine and materials science. 相似文献
12.
Visible‐Light‐Promoted Photocatalytic B−C Coupling via a Boron‐Centered Carboranyl Radical: Facile Synthesis of B(3)‐Arylated o‐Carboranes
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Dr. Da Zhao Prof. Dr. Zuowei Xie 《Angewandte Chemie (International ed. in English)》2016,55(9):3166-3170
A visible‐light‐mediated in situ generation of a boron‐centered carboranyl radical (o‐C2B10H11 . ) has been described. With eosin Y as a photoredox catalyst, 3‐diazonium‐o‐carborane tetrafluoroborate [3‐N2‐o‐C2B10H11][BF4] was converted into the corresponding boron‐centered carboranyl radical intermediate, which can undergo efficient electrophilic substitution reaction with a wide range of (hetero)arenes. This general and simple procedure provides a metal‐free alternative for the synthesis of 3‐(hetero)arylated‐o‐carboranes. 相似文献
13.
Konstantin A. Lyssenko Gennadii V. Grintselev‐Knyazev Mikhail Yu. Antipin Sergey P. Knyazev Valerii N. Kirin Eugenii A. Chernyshev 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):827-829
Two phenyl‐substituted carboranes, 3‐phenyl‐1,2‐dicarba‐closo‐dodecaborane(12), C8H16B10, (I), and 1‐phenyl‐1,7‐dicarba‐closo‐dodecaborane(12), C8H16B10, (II), were found to be isostructural. Comparison of the bond angles at the ipso‐C atoms of the phenyl substituent for (I) and (II) [117.71 (3) and 118.45 (10)°, respectively] indicates that electron donation of the carborane cage for B‐ and C‐substituted carboranes is different. 相似文献
14.
Synthesis of the First Example of the 12‐Vertex‐closo/12‐Vertex‐nido Biscarborane Cluster by a Metal‐Free B−H Activation at a Phosphorus(III) Center
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Dr. Yuen Onn Wong Dr. Mark D. Smith Prof. Dmitry V. Peryshkov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(20):6764-6767
An unusual 12‐vertex‐closo‐C2B10/12‐vertex‐nido‐C2B10 biscarborane cluster was synthesized through an unprecedented regioselective metal‐free B?H activation by a sterically hindered PIII center under mild conditions accompanied by cage‐opening rearrangement. A combination of the electron‐accepting properties of a carborane cage and steric enforcement of close interatomic contacts represent a new synthetic strategy for the activation of strong B?H bonds in carboranes. 相似文献
15.
Regioselective Insertion of o‐Carborynes into the α‐CH Bond of Tertiary Amines: Synthesis of α‐Carboranylated Amines
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Da Zhao Jiji Zhang Prof. Dr. Zuowei Xie 《Angewandte Chemie (International ed. in English)》2014,53(47):12902-12906
o‐Carboryne can undergo α‐C? H bond insertion with tertiary amines, thus affording α‐carboranylated amines in very good regioselectivity and isolated yields. In this process, the nucleophilic addition of tertiary amines to the multiple bond of o‐carboryne generates a zwitterionic intermediate. An intramolecular proton transfer, followed by a nucleophilic attack leads to the formation of the final product. Thus, regioselectivity is highly dependent upon the acidity of α‐C? H proton of tertiary amines. This approach serves as an efficient methodology for the preparation of a series of 1‐aminoalkyl‐o‐carboranes. 相似文献
16.
A Pd‐catalyzed three‐component carbonylative‐annulation of 1‐hydroxy‐o‐carborane, internal alkyne and carbon monoxide has been achieved via direct and regioselective cage B?H activation. A class of C,B‐substituted carborano‐coumarin derivatives with potential applications in pharmaceuticals were facilely prepared in moderate to high yields with excellent chemoselectivity and regioselectivity. A plausible reaction mechanism including CO insertion, electrophilic B?H metalation, alkyne insertion and reductive elimination was proposed. 相似文献
17.
Da Zhao Jiji Zhang Zuowei Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(47):13116-13120
o‐Carboryne can undergo α‐C H bond insertion with tertiary amines, thus affording α‐carboranylated amines in very good regioselectivity and isolated yields. In this process, the nucleophilic addition of tertiary amines to the multiple bond of o‐carboryne generates a zwitterionic intermediate. An intramolecular proton transfer, followed by a nucleophilic attack leads to the formation of the final product. Thus, regioselectivity is highly dependent upon the acidity of α‐C H proton of tertiary amines. This approach serves as an efficient methodology for the preparation of a series of 1‐aminoalkyl‐o‐carboranes. 相似文献
18.
Aggregation‐Induced Delayed Fluorescence Based on Donor/Acceptor‐Tethered Janus Carborane Triads: Unique Photophysical Properties of Nondoped OLEDs
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In Seob Park Jiyoung Lee Prof. Dr. Takuma Yasuda 《Angewandte Chemie (International ed. in English)》2016,55(25):7171-7175
Luminescent materials consisting of boron clusters, such as carboranes, have attracted immense interest in recent years. In this study, luminescent organic–inorganic conjugated systems based on o‐carboranes directly bonded to electron‐donating and electron‐accepting π‐conjugated units were elaborated as novel optoelectronic materials. These o‐carborane derivatives simultaneously possessed aggregation‐induced emission (AIE) and thermally activated delayed fluorescence (TADF) capabilities, and showed strong yellow‐to‐red emissions with high photoluminescence quantum efficiencies of up to 97 % in their aggregated states or in solid neat films. Organic light‐emitting diodes utilizing these o‐carborane derivatives as a nondoped emission layer exhibited maximum external electroluminescence quantum efficiencies as high as 11 %, originating from TADF. 相似文献
19.
Alberto V. Puga Dr. Francesc Teixidor Prof. Dr. Reijo Sillanpää Prof. Dr. Raikko Kivekäs Dr. Massimiliano Arca Dr. Gemma Barberà Dr. Clara Viñas Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(38):9755-9763
The incorporation of iodine atoms onto the boron vertices of the o‐carborane framework causes, according to spectroscopic data, a uniform increase in the acidic character of the Cc? H (Cc= cluster carbon) vertices, whereas the incorporation of methyl groups onto the boron vertices of the o‐carborane framework reduces their acidity. Methyl groups when attached to boron are electron‐withdrawing in boron clusters, whereas iodine atoms bonded to boron act as electron donors. This has been proven on B‐methyl and B‐iodinated o‐carboranes with NMR spectroscopy measurements and DFT calculations of natural bond orbital (NBO) charges, which show a cumulative buildup of positive cluster‐only total charge (CTC) on B‐methyl o‐carboranes and a cumulative buildup of negative cluster‐only total charge for B‐iodinated o‐carboranes. 相似文献
20.
Carborane Dyads for Photoinduced Electron Transfer: Photophysical Studies on Carbazole and Phenyl‐o‐carborane Molecular Assemblies
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Soonnam Kwon Kyung‐Ryang Wee Yang‐Jin Cho Prof. Sang Ook Kang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(20):5953-5960
o‐Carborane‐based donor–acceptor dyads comprising an o‐carboranyl phenyl unit combined with N‐carbazole ( 1 ) or 4‐phenyl‐N‐carbazole ( 2 ) were prepared, and their dyad characters were confirmed by steady‐state photochemistry and photodynamic experiments as well as electrochemical studies. The absorption and electrochemical properties of the dyads were essentially the sum of those of the carbazole and o‐carboranyl phenyl units; this indicates negligible interaction between the carbazole and o‐carborane units in the ground state. However, the emission spectra of 1 and 2 indicated that carbazole fluorescence was effectively quenched and a new charge‐transfer (CT) emission was observed in solvents, varying from hexane to acetonitrile, which exhibited large Stoke shifts. The CT emission properties of o‐carborane‐based dyads were further analyzed by using Lippert–Mataga plots to show that unit charge separation occurred to form a charge‐separated species in the excited state, namely, 1?2 . This excited‐state species was confirmed by nanosecond transient absorption spectra and spectroelectrochemical measurements; the photoexcitation of carbazole generated the CT state in which a radical cation and anion were formed at the carbazole and o‐carborane units, respectively, within a few nanoseconds. DFT calculations corroborated the presence of this CT species and showed localized populations of the highest singly occupied molecular orbital on 2 in the reduced anionic state. As a result, molecular assemblies formed by linking the carbazole group with the o‐carborane cage through a phenylene or multi‐phenylene spacer revealed that the photoinduced electron‐transfer process occurred intramolecularly. 相似文献