Diastereoselective allylation and crotylation of N-unsubstituted imines derived from ketones
作者:Bhartesh Dhudshia、Jorge Tiburcio、Avinash N. Thadani
DOI:10.1039/b511411j
日期:——
A wide variety of tertiary carbinamines are synthesized in high yields via diastereoselective allylation and crotylation of in situ generated N-unsubstituted ketimines.
通过立体选择性的烯丙基化和巴豆基化反应,在原位生成了未取代的N-酮亚胺,进而高效合成了多种叔碳胺。
Potassium allyl- and crotyltrifluoroborates: Stable and efficient agents for allylation and crotylation
作者:Robert A. Batey、Avinash N. Thadani、David V. Smil
DOI:10.1016/s0040-4039(99)00774-1
日期:1999.6
Potassium allyl- and crotyltrifluoroborates react rapidly with aldehydes in the presence of BF3·Et2O. These salts are stable to air and moisture, and lead to adducts in high yield and with high diastereoselectivity. The stereochemistry of the crotylated products is consistent with the reaction via allylboron difluoride and a Zimmerman-Traxler like transition state.
Base-free nickel-catalysed decarbonylative Suzuki–Miyaura coupling of acid fluorides
作者:Christian A. Malapit、James R. Bour、Conor E. Brigham、Melanie S. Sanford
DOI:10.1038/s41586-018-0628-7
日期:2018.11
Suzuki–Miyaura-type reactions to proceed without an exogenous base12–14. Here we use this approach to develop a nickel-catalysed coupling of aryl boronic acids with acid fluorides15–17, which are formed in situ from readily available carboxylic acids18–22. This combination of catalyst and electrophile enables a mechanistic manifold in which a ‘transmetallation-active’ aryl nickel fluorideintermediate is generated
Ligand-controlled reactivity plays an important role in transition-metal catalysis, enabling a vast number of efficient transformations to be discovered and developed. However, a single ligand is generally used to promote all steps of the catalytic cycle (e.g., oxidative addition, reductive elimination), a requirement that makes ligand design challenging and limits its generality, especially in relay
tertiary alcohols represents a recurrent challenge in organic synthesis. In the present paper, we describe a simple, efficient, and indirect method to enantioselectively prepare tertiary alcohols through a chiral isothiourea catalyzed selective acylation of adjacent secondaryalcohols. This transformation enables the kinetic resolution (KR) of easily prepared racemic diastereoenriched secondary/tertiary