A Facile Synthesis of N-Boc-Protected Pyrroles by Cyclodehydration of γ-Amino-α,β-enals and -enones
摘要:
A novel series of N-Boc-substituted and fused pyrroles was prepared by cyclodehydration of readily accessible (E)-gamma-(tert-butoxycarbonylamino)-alpha,beta-enals and -enones. Functionalisation of the pyrrole ring was then explored with 2-borylated pyrroles in the Suzuki-Miyaura coupling.
The value of 2 J P–CO as a diagnostic parameter for the structure and thermal reactivity of carbonyl-stabilised phosphonium ylides
作者:R. Alan Aitken、Youcef Boubalouta、Da Chang、Lee P. Cleghorn、Ian P. Gray、Nazira Karodia、Euan J. Reid、Alexandra M.Z. Slawin
DOI:10.1016/j.tet.2017.09.016
日期:2017.11
A survey of 20 carbonyl-stabilised phosphonium ylides with recently reported X-ray structures shows a strong correlation between the CP to CO torsion angle and the value of 2JP–CO, with high values being associated with an anti configuration and low with syn. Seven new X-ray structural determinations are reported, several for types of ylide not crystallographically characterised before, and these also
1-Cycloalkyl phosphonium salts represented by the formula ##STR1## wherein: R is selected from the group consisting of lower alkyl, hydroxy lower alkyl, halo lower alkyl, amino lower alkyl, cyano lower alkyl, lower alkenyl with the limitation that the double bond is not on the carbon atom attached to the oxygen atom, benzyl, substituted benzyl and ##STR2## wherein q is 0 or 1 and R.sub.4 is selected from the group consisting of hydroxy, loweralkoxy, phenyl, substituted phenyl, and ##STR3## wherein R.sub.5 and R.sub.6 are the same or different members of the group consisting of hydrogen and loweralkyl or taken together form a 5 or 6 membered ring; m is 1, 2 or 3; n is 0 or 1; o is 0 or 1; p is 0 or 1; R.sub.1, R.sub.2 and R.sub.3 are the same or different members of the group consisting of hydrogen, lower alkyl, lower alkoxy and halo; and X is a pharmaceutically acceptable anion. The compounds are useful as analgesic agents.
Palladium‐Catalyzed Cyclizative Borylation of Allenyl Ketones through Carbene Boryl Migratory Insertion: Access to Densely Substituted Furyl Boronates
作者:Kang Wang、Yan Xu、Jianbo Wang
DOI:10.1002/chem.202203697
日期:2023.3
A highly efficient Pd-catalyzed cyclizative borylation reaction of allenyl ketones has been developed. The transformation is based on carbene boryl migratoryinsertion using starting materials that are modularly assembled from raw building blocks. This borylation reaction is a reliable method to synthesize various borylated furans, from which previously hard-to-obtain tetra-substituted furans can be