Palladium-Catalyzed Distannylation of ortho-Quinodimethanes
摘要:
An exo-diene moiety of various ortho-quinodimethanes, regardless of its transient character, was inserted into a Sn-Sn sigma-bond of hexabutyldistannane in the presence of a palladium catalyst, giving alpha,alpha'-bis(tributylstannyl)-o-xylenes straightforwardly.
Tetrahydro-as-indacenyl catalyst composition, catalyst system, and processes for use thereof
申请人:ExxonMobil Chemical Patents Inc.
公开号:US09803037B1
公开(公告)日:2017-10-31
This invention relates to a compound represented by the formula: TyLAMXn-2 wherein: A is a substituted or unsubstituted tetrahydro-as-indacenyl group bonded to M; L is substituted or unsubstituted monocyclic or polycyclic arenyl ligand or monocyclic or polycyclic heteroarenyl ligand bonded to M; M is a group 3, 4, 5, or 6 transition metal (preferably group 4); T is a bridging group bonded to L and A; y is 0 or 1, indicating the absence or presence of T; X is a leaving group, typically a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene; n is the oxidation state of M and is 3, 4, 5, or 6.
Solvent and leaving group effects on the mono- vs. Dialkylation of alkali salts of diethyl malonate with 1,2-bis-, 1,2,4,5-tetrakis- and 1,2,3,4,5,6-hexakis-(Halomethyl)benzenes. A new insight into selectivity control of malonester synthesis
protic (“acidic”) solvents favor monoalkylation whereas aprotic (“inert”) solvents support dialkylation of diethyl malonate carbanion, exactly opposite results have been obtained in the reaction of the dibromide 7, tetrabromide 4 and hexabromide 1 in ethanol and dimethyl sulfoxide, the former solvent preferring strongly dialkylation (cyclization) and the latter monoalkylation. Investigation in a broader
Mono- vs. dialkylation of carbanions. Effects of absolute and relative acidity of the conjugate carbon acids in selectivity control
作者:Luděk Ridvan、Jiří Závada
DOI:10.1016/s0040-4020(97)00989-7
日期:1997.10
in the reaction of the dibromide 1 with carbanions 2a – 2g covering a range greater than 15 pK units in DMSO. It was found that the bis(monoalkylated) product 3 arises exclusively or predominantly from the carbanions 2d – 2g derived from the less acidic carbon acids 7d – 7g whereas the cyclic product of dialkylation 4 prevails in the reaction of the carbanions 2a – 2c derived from the more acidic carbon
The disclosure is related to EMM-31 materials, processes, and uses of the same as well as reagents used in the preparation of the EMM-31 materials, process and intermediates for preparing these reagents.
The disclosure is related to EMM-31 materials, processes, and uses of the same as well as reagents used in the preparation of the EMM-31 materials, process and intermediates for preparing these reagents.