High-Load, Soluble Oligomeric Carbodiimide: Synthesis and Application in Coupling Reactions
作者:Mianji Zhang、Punitha Vedantham、Daniel L. Flynn、Paul R. Hanson
DOI:10.1021/jo048870c
日期:2004.11.1
A facile preparation of a high-load, soluble oligomeric alkyl cyclohexylcarbodiimide (OACC) reagent via ROM polymerization from commercially available starting materials is described. This reagent is exploited as a coupling reagent for esterification, amidation, and dehydration of carboxylicacids (aliphatic and aromatic) with an assortment of alcohols (aliphatic primary, secondary, and benzylic),
Nickel-Catalyzed Directed Cross-Electrophile Coupling of Phenolic Esters with Alkyl Bromides
作者:Feiyan Yang、Decai Ding、Chuan Wang
DOI:10.1021/acs.orglett.0c03342
日期:2020.12.4
electrophilic acyl source in the reaction with diverse primary and secondary unactivated alkyl bromides. The cleavage of the relatively inert C–O bond is facilitated by the neighboring coordinating hydroxyl or sulfonamide moiety. By circumventing the use of pregenerated organometallics, this method allows efficient preparation of a variety of o-hydroxyl and tosyl-protected o-amino aryl ketones with high compatibility
involving an alkyl radicalgeneratedfrom a primary alcohol by photochemistry are rare and challenging. Herein, we present a photocatalyst- and metal-free approach that enables the generation of an alkyl radicalfrom the corresponding alcohol and the subsequent C(sp3)–C(sp3) bond formation with activated olefin, via an alkyl thianthrenium salt/Hantzsch ester electron donor–acceptor complex. This protocol
Selective Monoesterification of Symmetrical Diols Using Resin-Bound Triphenylphosphine
作者:Gunindra Pathak、Samuel Lalthazuala Rokhum
DOI:10.1021/acscombsci.5b00086
日期:2015.9.14
Coupling reactions to make esters and amides are among the most widely used organic transformations. We report efficient procedures for amide bond formation and for the monoesterification of symmetrical diols in excellent yields without any requirement for high dilution or slow addition using resin-bound triarylphosphonium iodide. Easy purification, low moisture sensitivity, and good to excellent yields
Photoinduced Palladium-Catalyzed Regio- and Chemoselective Elimination of Primary Alkyl Bromides: A Mild Route to Synthesize Unactivated Terminal Olefins
作者:Sen Yang、Hao Hu、Ming Chen
DOI:10.1021/acs.orglett.3c02980
日期:2023.11.10
yielding unactivated terminalolefins vital in organic synthesis. Achieved through ligand control, the reaction exhibits remarkable regioselectivity and suppresses undesired side reactions, particularly 1,5-hydrogen atom transfer (HAT). The process favors primary alkyl halides while preserving secondary and tertiary alkyl bromides, thereby enabling the incorporation of terminalolefins in complex molecules