Enhanced slip distortions in 1-phenyl-2-methyldicarbaplatinaboranes. Conformational destabilisation in the isomerisation of 1-phenyldicarbaplatinaboranes
摘要:
The compounds Tl-2[7-Ph-8-Me-7,8-nido-C2B9H9], [C5H10NH2] [7-Ph-8-Me-7,8-nido-C2B9H10], 1-Ph-2-Me-3,3-L(2)-3,1,2-PtC2B9H9 [L = PMe(2)Ph, PEt(3), PPh(3) or P(C(6)H(4)Me-p)(3)] have been prepared and characterised. The platinum complexes were obtained from the reactions between Tl-2[7-Ph-8-Me-7,8-nido-C2B9H9] and the appropriate [PtCl2(PR(3))(2)] species. Crystallographic studies upon the compounds where L = PEt(3) and two crystalline modifications of that where L = PPh(3) afforded evidence of a substantial influence of intramolecular crowding upon the observed structures, so that the lateral slippage (Delta) of the metal fragment is significantly enhanced: Delta = 0.74 and 0.94 and 0.91 Angstrom respectively. These compounds do not isomerise under conditions which produce rearrangement in the corresponding (less-congested) derivatives of 1-phenylcarbaborane, consistent with the proposed conformational destabilisation in the latter system.
Nickel-Catalyzed Cross-Coupling Reactions of<i>o</i>-Carboranyl with Aryl Iodides: Facile Synthesis of 1-Aryl-<i>o</i>-Carboranes and 1,2-Diaryl-<i>o</i>-Carboranes
作者:Cen Tang、Zuowei Xie
DOI:10.1002/anie.201502502
日期:2015.6.22
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.
Palladium-Catalyzed Selective Mono-/Tetraacetoxylation of <i>o</i>-Carboranes with Acetic Acid via Cross Dehydrogenative Coupling of Cage B–H/O–H Bonds
作者:Tao-Tao Xu、Ke Cao、Ji Wu、Cai-Yan Zhang、Junxiao Yang
DOI:10.1021/acs.inorgchem.8b00038
日期:2018.3.5
with acetic acid via cross dehydrogenative coupling of cage B–H/O–H bonds has been developed, and a series of mono- and tetraacetoxylated o-carboranes have been synthesized with moderate to good yields as well as good selectivity. Mechanistic studies indicate that the acetoxyl originates from acetic acid directly, and a nucleophilic addition of PdIV-oxo species and dehydration process is proposed.
The B(9)-H halogenation of o-carborane and m-carborane was achieved with excellent selectivities in hexafluoroisopropanol (HFIP) under simple reaction conditions: single reagent [trichloroisocyanuric acid (TCCA), tribromoisocyanuric acid (TBCA) or N-iodosuccinimide (NIS)], catalyst-free, air-/moisture-tolerant, and convenient work-up. With this method, a variety of 9-halogenated o-carboranes and m-carboranes
Light-promoted copper-catalyzed cage C-arylation of <i>o</i>-carboranes: facile synthesis of 1-aryl-<i>o</i>-carboranes and <i>o</i>-carborane-fused cyclics
作者:Hangcheng Ni、Zhenpin Lu、Zuowei Xie
DOI:10.1039/d0nj02029j
日期:——
Light-promoted, coppercatalyzed cage C–H arylation of o-carboranes with aryl halides has been achieved, leading to the facile synthesis of a variety of 1-aryl-o-carboranes and o-carborane-fused cyclics. This method has the following features: (1) using o-carboranes instead of prefunctionalized iodocarboranes as starting materials; (2) employing earth abundant copper as a catalyst; and (3) room-temperature