120651-33-4Relevant academic research and scientific papers
Five-State Rotary Nanoswitch
Gaikwad, Sudhakar,Schmittel, Michael
, p. 343 - 352 (2017)
In our quest to develop artificial multistate devices, we synthesized the nanomechanical switch 1 that is characterized by a tetrahedral core equipped with four pending arms. The rotary arm with its azaterpyridine terminal is intramolecularly coordinated to a zinc(II) porphyrin station that is the terminus of another arm in 1. The two other arms carry identical sterically shielded phenanthroline stations. The 2-fold alternate addition of a copper(I) ion and [1,10]-phenanthroline (1 equiv each) results in the formation of five different switching states (State I→ State II→ State III→ State IV→ State V → State I), which force the toggling arm to move back and forth between the zinc(II) porphyrin and phenanthroline stations separated by a distance of 25 ?. All switching states constitute clean single species, except for State III, and thus are fully characterized by spectroscopic methods and elemental analysis. Finally, the initial state of nanoswitch was reset by addition of cyclam for complete removal of the copper(I) ions.
Reversible Multicomponent and Gate Triggered by Stoichiometric Chemical Pulses Commands the Self-Assembly and Actuation of Catalytic Machinery
Biswas, Pronay Kumar,Saha, Suchismita,Gaikwad, Sudhakar,Schmittel, Michael
, p. 7889 - 7897 (2020)
The present work demonstrates the operation of a reversible supramolecular gate, i.e., an ensemble of various components linked by chemical communication, which is triggered by stoichiometric chemical inputs and by obeying the AND truth table delivers a s
Dual Gold-Catalyzed Three-Component Reaction: Efficient Synthesis of Indene-Fused Esters, Acids, and Lactones through Gold Vinylidene Intermediates
Yu, Congjun,Ma, Xiaodong,Chen, Bin,Tang, Bencan,Paton, Robert S.,Zhang, Guozhu
, p. 1561 - 1565 (2017)
A dual gold(I)-catalyzed three-component reaction was developed to prepare indene-fused carboxylic acid derivatives from diynes, alcohols, and pyridine N-oxides in both inter- and intramolecular fashions. The pyridine N-oxides were found to exhibit distinct selectivity unlike the α-oxo gold carbene intermediates in the well-developed gold-catalyzed oxidative functionalization of alkynes. Experimental studies and DFT calculations support double nucleophilic substitution of a gold vinylidene intermediate.
Gold Catalysis Meets Materials Science – A New Approach to π-Extended Indolocarbazoles
Hendrich, Christoph M.,Bongartz, Lukas M.,Hoffmann, Marvin T.,Zschieschang, Ute,Borchert, James W.,Sauter, Désirée,Kr?mer, Petra,Rominger, Frank,Mulks, Florian F.,Rudolph, Matthias,Dreuw, Andreas,Klauk, Hagen,Hashmi, A. Stephen K.
supporting information, p. 549 - 557 (2020/12/07)
Herein we describe a modular, convergent synthesis of substituted benzo[a]benzo[6,7]-indolo[2,3-h]carbazoles (BBICZs) using a bidirectional gold-catalyzed cyclization reaction as a key step. A building block strategy enabled the easy variation of substituents at different positions of the core structure and a general analysis of substitution effects on the materials properties of the target compounds. All BBICZs were fully characterized and their optical and electronic properties were studied experimentally as well as by computational methods. Organic thin-film transistors based on eight selected derivatives were fabricated by vacuum deposition and charge-carrier mobilities up to 1 cm2/Vs were measured. (Figure presented.).
One-pot transformation of Me3Si-/Ph2P(O)-protected ethynes to unsymmetrical arylethynes
Peng, Li-Fen,Lei, Jia-Ying,Wu, Li,Tang, Zi-Long,Luo, Zhi-Peng,Jiao, Yin-Chun,Xu, Xin-Hua
, p. 271 - 273 (2018/06/26)
Me3Si-/Ph2P(O)-protected ethynes were successfully transformed to unsymmetrical arylethynes via a one-pot Ph2P(O)-deprotection/ [Pd(dppf)Cl2]-catalysed coupling and one-pot Me3Si-deprotection/Sonogash
Dual Gold Catalysis: Synthesis of Fluorene Derivatives from Diynes
Bucher, Janina,Wurm, Thomas,Taschinski, Svenja,Sachs, Eleni,Ascough, David,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
supporting information, p. 225 - 233 (2017/02/05)
1,5-Diyne systems bearing one terminal and one benzyl- or allyl-substituted alkyne attached to an aromatic backbone were converted in the presence of a gold catalyst. In a dual gold-catalyzed process, gold vinylidenes are formed that selectively undergo formal CH insertion into the C(sp2)–H bond of the offered unsaturated systems. If H atoms are present in the propargylic position, a subsequent isomerization to the aromatic system takes place leading to 9H-fluorene and 11H-benzo[b]fluorene derivatives as final products. In the case of a quaternary carbon in the propargylic position no further aromatization is observed and 10H-benzo[b]fluorene derivatives are obtained in high yield. (Figure presented.).
CO extrusion in homogeneous gold catalysis: Reactivity of gold acyl species generated through water addition to gold vinylidenes
Bucher, Janina,St?sser, Tim,Rudolph, Matthias,Rominger, Frank,Hashmi, A. Stephen K.
, p. 1666 - 1670 (2015/01/30)
Herein, we describe a new gold-catalyzed decarbonylative indene synthesis. Synergistic σ,π-activation of diyne substrates leads to gold vinylidene intermediates, which upon addition of water are transformed into gold acyl species, a type of organogold compound hitherto only scarcely reported. The latter are shown to undergo extrusion of CO, an elementary step completely unknown for homogeneous gold catalysis. By tuning the electronic and steric properties of the starting diyne systems, this new reactivity could be exploited for the synthesis of indene derivatives in high yields.
Selective deprotection of Me3Si-/Ph2P(O)-protected arylalkynes: Methyl Grignard reagent-promoted dephosphorylation of Ph2P(O)-protected alkynes
Peng, Lifen,Xu, Feng,Shinohara, Kenta,Orita, Akihiro,Otera, Junzo
supporting information, p. 1610 - 1612 (2014/12/11)
A Ph2P(O)-protected alkyne underwent dephosphorylation by treatment with MeMgBr in THF with Me3Si-protection untouched. The dephosphorylation followed by a transition-metal-catalyzed coupling of the resulting terminal a lkyne with aryl halides was carried out in a one-pot manner to afford the desired coupling product. Selective deprotection of Me3Si-/Ph2P(O)-protected alkynes enabled facile syntheses of expanded π-systems such as cyclic phenyleneethyny lenes and unsymmetrically substituted ditriazol.
Molecular propellers that consist of dehydrobenzo[14]annulene blades
Nobusue, Shunpei,Mukai, Yuichi,Fukumoto, Yo,Umeda, Rui,Tahara, Kazukuni,Sonoda, Motohiro,Tobe, Yoshito
supporting information, p. 12814 - 12824,11 (2020/09/14)
A new class of propel- ler-shaped compound (4), which consisted of dehydrobenzo[14]annulene ([14]DBA) blades, as well as its naphtho homologues (5 and 6), have been prepared. Although NMR studies of compound 4 did not provide useful information regarding
Oligosaccharide Analogues of Polysaccharides. Part 3. A New Protecting Group for Alkynes: Orthogonally Protected Dialkynes
Cai, Chengzhi,Vasella, Andrea
, p. 732 - 757 (2007/10/02)
Dialkynes of the type 3 (Scheme 1) are regioselectively deprotected by treating them either with base in a protic solvent (-> 4), or - after exposing the OH group - by catalytic amounts of base in an aprotic solvent (-> 5 and 8).The Me3Si-protected 12 (Sc
