Bispropargylic Alcohols Research Articles

Highly Efficient One-Pot Synthesis of 2,4,5-Trisubstituted 3(2H)-Furanones Utilizing a Au(I)-Catalyzed Oxidation/Pinacol Rearrangement/anti-Michael Cascade.

A highly efficient Au(I)-catalyzed cascade reaction between bispropargylic alcohols and pyridine-N-oxides has been realized. The reaction process involved a gold(I)-catalyzed sequential oxidation/Pinacol rearrangement/oxacyclization. Moreover, 1,2-aryl, 1,2-alkyl, or 1,2-vinyl migration was favored over 1,2-alkynyl in the crucial gold(I)-catalyzed Pinacol rearrangement step. A range of 2,4,5-trisubstituted 3(2H)-furanones were synthesized in high yields (up to 88%) with excellent regioselectivities (up to >19:1) under mild reaction conditions.

An Efficient Stereoselective Synthesis of cis-2,6-Disubstituted Tetrahydropyrans via Gold-Catalyzed Meyer–Schuster Rearrangement/Hydration/oxa-Michael Addition Sequence

An efficient stereoselective synthesis of cis-2,6-disubstituted tetrahydropyrans 14a–c has been achieved via gold-catalyzed Meyer–Schuster rearrangement/hydration/oxa-Michael addition sequence from bis-propargylic alcohols 13a–c. The reaction of 13a proceeds via 2,6-disubstituted tetrahydropyran 14′a as an intermediate.

Phosphorus-Containing Bis-allenes: Synthesis and Heterocyclization Reactions Mediated by Iodine or Copper Dibromide.

Bisphosphorylallenes were easily obtained in multigram scale from the Wittig-type rearrangement of bispropargyl alcohols. Unlike other conjugated bis-allenes, these reagents underwent a double cyclization mediated by iodine or copper dibromide leading to the formation of bis-1,2-oxaphospholenes.

Iron cyclopentadienone complexes derived from C2-symmetric bis-propargylic alcohols; preparation and applications to catalysis

A series of complexes containing the iron-cyclopentadienone structure were prepared by cyclising bis-propargylic alcohols and their derivatives with iron pentacarbonyl. The resulting complexes were characterised and tested in the catalysis of ketone reduction and alcohol oxidation. The complexes are competent catalysts for ketone reduction and alcohol oxidations.

TfOH-Catalyzed Reaction of Bispropargyl Alcohols with 1,3-Dicarbonyl Compounds

A transition-metal-free efficient method for the preparation of 1,2,3-trisubstituted benzenes from bispropargyl alcohols and 1,3-dicarbonyl compounds has been developed. The reaction of bispropargyl alcohol with 1,3-dicarbonyl compound proceeds through [3,3]-rearrangement, 6π-electrocyclization, and unexpected Csp3−Csp2 regioselective σ-bond cleavage processes.

Convenient synthesis of naphthopyrans using montmorillonite K-10 as heterogeneous catalyst

A simple and mild procedure for the synthesis of different naphthopyrans providing high yields in a short reaction time was reported. The reaction of propargylic alcohols with α- or β-naphthol and dihydroxy naphthalenes in the presence of montmorillonite K-10 was studied. This reaction afforded high yields of the corresponding naphthopyrans. In addition, a number of new phenylene and biphenylen-linked bisnaphthopyrans were synthesized providing excellent yields via the one-pot reaction of bis-propargyl alcohols with β-naphthol. A simple, mild and efficient procedure for the synthesis of different naphthopyrans including novel naphthopyrans with fluorene and ferrocene moieties is reported. The reaction of propargylic alcohols with α-or β-naphthol and dihydroxy naphthalenes in the presence of montmorillonite K-10 was studied and afforded high yields of the corresponding naphthopyrans.

Silver-Catalyzed Carbon Dioxide Incorporation and Rearrangement on Propargylic Derivatives

Abstract A silver/DBU catalyst system was developed for the effective synthesis of cyclic carbonate and oxazolidinone from the reaction of CO2 with propargylic alcohols and propargylic amines, respectively, in high yields under mild conditions. It was found that the [3,3]-sigmatropic Meyer–Schuster-type rearrangement of the propargylic alcohol was mediated by CO2 in DMF to afford the corresponding α,β-unsaturated carbonyl compounds in high yields. The silver salt combined with the chiral Schiff base ligand could be applied to enantioselective chemical CO2 incorporation into various bispropargylic alcohols to produce the corresponding cyclic carbonate in high yields with high enantioselectivity. The absolute configuration was determined by VCD spectroscopy as well as by X-ray analysis. These products were found to be active for the aminolysis reaction to afford the corresponding carbamate derivatives in high yields without any loss of optical purity.

New Bridges in [2.2]Paracyclophanes: The Interaction of Chalcogenide Halides with Pseudo-Geminal Triple Bonds

Novel heteroatom containing bridges have been introduced in [2.2]paracyclophanes by the interaction of chalcogenide halides with pseudo-geminal triple bonds. The anti-addition with Markovnikov orientation of selenium halides to 4,15-bisethynyl[2.2]paracyclophane leads to the corresponding E-adducts. The interaction of pseudo-geminally substituted bispropargylic alcohols with disulfur dichloride and sulfur dichloride leads to a mixture of cyclic ethers. These compounds are formed under mild acidic conditions provided by the organic ammonium chlorides or silica gel. The corresponding dipropargyloxy sulfides have been identified as reaction intermediates. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

ChemInform Abstract: A New Bridge in [2.2]Cyclophanes: The Addition of Se2Cl2 to Pseudogeminally Substituted Bispropargylic Alcohols.

AbstractThe title reaction provides a mixture of the expected diselenides (III) along with monoselenides and triselenides.

Silver-Catalyzed Enantioselective Carbon Dioxide Incorporation into Bispropargylic Alcohols

The combined catalyst system of silver acetate with a chiral Schiff base ligand achieved asymmetric carbon dioxide incorporation into bispropargylic alcohols with desymmetrization to afford the corresponding cyclic carbonates with good-to-excellent enantiomeric excesses.

A new bridge in [2.2]cyclophanes: The addition of Se2Cl2 to pseudogeminally substituted bispropargylic alcohols

AbstractThe regio‐ and stereo‐specific addition of monoselenium monochloride to pseudogeminally substituted bispropargylic alcohols has been performed under high dilution conditions. The disproportionation reaction of selenium monochloride to selenium dichloride and triselenium dichloride leads to the corresponding divinylic mono‐ and tri‐selenides. The stereochemistry of the newly generated double bond was assigned as Z by 2D NMR experiments. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:126–130, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20586

Intramolecular Cyclizations of Co2(CO)6-Complexed Propargyl Radicals: Synthesis ofd,l- andmeso-1,5-Cyclodecadiynes

Intramolecular radical cyclizations of Co2(CO)6-complexed bis-propargyl alcohols 1−5 provide an easy, two-step access to the otherwise hardly accessible d,l- and meso-3,4-diaryl-1,5-cyclodecadiynes 21−25. The acid-induced generation of bis-cations 6−10 is followed by reduction with a 100-fold excess of zinc, generating key reactive intermediates, i.e. the cobalt-complexed bis-propargyl radicals 11−15. The substitution pattern (0-, 4-, 3,4-, 3,4,5-) and the nature of aromatic substituents (H, i-Pr, OMe) are found essential both to the diastereoselectivity of the process—with d,l:meso ratios varying from 54:46 to 80:20—and the isolability of individual stereoisomers. In particular, an accumulation of methoxy groups on the periphery of the aromatic rings facilitates separation in both intra- and intermolecular reactions. The observed disparity in the level of diastereoselection in intra- and intermolecular reactions is accounted for on the basis of conformational analysis, calculation data for cobalt-complexed propargyl radicals, and the concept of a CH/π coordination. The new knowledge thus acquired has a predicting power, allowing future substrates to be designed, both topologically and stereoelectronically, in a manner favoring either d,l or meso diastereomers.

Synthesis and Photochromism of Novel Phenylene-Linked Photochromic Bispyrans

[reaction: see text] Phenylene-linked bisnaphthopyrans were synthesized in good yields via the one-pot reaction of bis-propargyl alcohols with naphthols. Temperature-dependent photochromism in 1,4-phenylene-linked bispyrans leads to up to 60 nm bathochromic shift between the colored species formed at room temperature and at -20 degrees C. Better fatigue resistance and higher colorability was observed in 1,4-phenylene-linked bis-[2H]-naphtho[1,2-b]pyrans by comparison to the 1,3-phenylene linked bis-[2H]-naphtho[1,2-b]pyrans.