Determining the σ-donor ability of the cyclopropane C–C bond
作者:Nathan L. Fifer、Jonathan M. White
DOI:10.1039/b503124a
日期:——
The low temperature crystal structures of ester and ether derivatives of varying electron demand, derived from cyclopropylmethanol 8 and dicyclopropylmethanol 9, have been determined. These structures show a very strong response of the CâOR bond distance to the electron demand of the OR substituent, demonstrating the strong Ï-donor ability of the strained CâC bonds in the cyclopropane ring.
reactions have achieved great success for accessing carbon–carbon and carbon–heteroatom bonds during the past decade, metal-free acceptorless dehydrogenative cross coupling is still scarce and highly desirable. Herein we report a robust metal-free acceptorless dehydrogenative cross-coupling for both carbon–heteroatom and carbon–carbonbondformation. By synergistic catalysis of the organophotocatalyst
Aerobic oxidative esterification and thioesterification of aldehydes using dibromoisocyanuric acid under mild conditions: no metal catalysts required
作者:Young-Do Kwon、Minh Thanh La、Hee-Kwon Kim
DOI:10.1039/c8nj01085d
日期:——
thioesters were synthesized by oxidative esterification and thioesterification via in situ generated acyl bromide intermediates, which were used to react with various alcohols and thiols. The esterification and thioesterification were readily performed in the presence of dibromoisocyanuric acid in dichloromethane, without any metal catalysts and undermildconditions. By using this reaction protocol
ortho/para-functionalized amine scaffolds from arylhydroxylamines is described. The transformation was featured with new electrophilic trifluoromethylthiolated reagents, good functional group tolerance, and late-stage modification of complex bioactive scaffolds, providing a rapid access to prepare numerous trifluoromethyl- and difluoromethyl-substituted sulfoxides. Mechanism studies and density functional