Synthesis of Stannyl‐Substituted d‐Glucal Derivatives via Palladium‐Catalyzed Regioselective Hydrostannation and Their Synthetic Applications

Abstract

Stannyl derivatives of 2-alkenyl acetylated D-glucals have been synthesized via palladium-catalyzed regioselective hydrostannation in good yields under mild reaction conditions. Factors affecting the regioselectivity of hydrostannation including chelation by the neighbouring acetyl-oxygen and the electronic effect of the substituent R on alkyne have been evaluated. The synthetic applications of these stannyl derivatives of D-glucal are shown by performing Stille and Sonogashira cross-coupling reactions to obtain a library of substituted 2-alkenyl derivatives of D-glucal.

2-Iodo-1-C-acceptor-substituted glycals: synthesis and transformation into 1,2-C,C-disubstituted glycals via Suzuki–Miyaura coupling reaction

“…Chemical shifts are referenced to TMS as the internal reference ( 1 H), or to the residual solvent signals ( 13 C). The assignment of the 1 H and 13 C NMR signals of compound 12d performed by their COSY, HSQC spectra. Mass spectra was performed with maXis II UHR ESI-QTOF MS (Bruker Daltonik, Bremen, Germany) instruments in positive ion mode with electrospray ionization technique or Thermo LTQ XL (Thermo Paper NJC…”

“…11 O -Acetylated 2-iodoglycals were used in the synthesis of 2- C -alkynylglycals under copper free Sonogashira conditions (Pd(OAc) 2 /PPh 3 /Cs 2 CO 3 /DMF) with alkyl/aryl/hetaryl substituted ethynes furnishing the desired derivatives with good to excellent yields (80–96%). 12,13 Palladium(0)-catalyzed carbonylative coupling reactions of 2-haloglycals such as aminocarbonylation, 14,15 alkoxy-/aryloxycarbonylation 14 or alkyl-, alkynyl-, aryl- and hetarylcarbonylation in the presence of CO or Mo(CO) 6 16–18 were used for the preparation of 2- C -branched carbohydrate derivatives. A simple synthesis of 2-cyanoglycals in a palladium-catalyzed reaction with protected and unprotected 2-iodoglycals was also reported.…”

Synthesis of Sugar-Based Enones and Their Transformation into 3,5-Disubstituted Furans and 2-Acyl-Substituted 1,2,3-Trideoxy Sugars in the Presence of Lewis Acids

“…Enones such as arylones and ynones, in which the keto functionality is attached to aromatic or alkyne moieties, are abundant in several bioactive natural products, pharmaceuticals, and cosmetics . These moieties also offer opportunities for further synthetic modifications. , Based on our experience in glycal chemistry, herein, we explore carbonylation using 2-iodoglycals with different coupling partners such as phenyl boronic acids and acetylene for the first synthesis of sugar-based arylones and ynones (Scheme ). Once arylones were formed, we investigated their behavior toward Lewis acid in the absence or presence of external nucleophiles for the synthesis of C-2-substituted 1,2,3-trideoxy sugars, natural product scaffolds, and 3,5-disubstituted furan derivatives containing a chiral side chain.…”