Styrene as 4π-Component in Zn(II)-Catalyzed Intermolecular Diels–Alder/Ene Tandem Reaction

Abstract

A mild Zn-catalyzed intermolecular Diels-Alder/ene tandem reaction with styrene as a 4π-component is reported. A variety of dihydronaphthalene products could be prepared in moderate to good yields. Moreover, a combination of DFT calculations and experiments was performed to further understand the mechanism of this unique tandem reaction.

Covalent Adaptable Networks with Tunable Exchange Rates Based on Reversible Thiol–yne Cross‐Linking

“…Alkynones 10 – 12 were chosen to evaluate the effect of substituents directly bound to the alkyne function. All alkynones were synthesized according to known literature procedures (see the Supporting Information), except for alkynones 1 , 2 and 12 , which are commercially available.…”

Covalent Adaptable Networks with Tunable Exchange Rates Based on Reversible Thiol–yne Cross‐Linking

“…Alkynones 10 – 12 were chosen to evaluate the effect of substituents directly bound to the alkyne function. All alkynones were synthesized according to known literature procedures (see the Supporting Information), except for alkynones 1 , 2 and 12 , which are commercially available.…”

“…Thes ubstituents directlyboundtothe alkynefunction(Scheme 2, R 1 ), as well as the substituents directly bound to thec arbonyl function( R 2 ) were varied with thei ntent to probeb oth steric ande lectronic effects on thedynamicexchange.Inthisseries of alkynones,but-3-yn-2-one (X = 1)was arbitrarily selected as thebenchmark to which allother alkynones willbecompared.Alkynones 2, 13-15 were chosent oe valuate the effecto fr eplacing the ketone functionality with an ester,a mide,s ulfonamide, or sulfone, respectively,a st hese area lso common moieties in polymer chemistry.A lkynones 3-9 represent derivatives of 1-phenylprop-2-yn-1-one,w hich allowedt he exploration of theh ypothetical control on thee xchange through introductiono f electronically (de)activating para-substituents.A lkynones 10-12 were chosen to evaluate thee ffect ofs ubstituentsd irectly boundt ot he alkyne function. All alkynonesw ere synthesized according to known literature procedures [37][38][39][40][41][42] (see theSupport-ingI nformation),e xceptf or alkynones 1, 2 and 12,w hich are commerciallyavailable.…”

A General Asymmetric Synthesis of (R)-Matsutakeol and Flavored Analogs

“…As shown in Scheme 4 , ( S )-BINOL efficiently catalyzed the asymmetric addition of trimethylsilylacetylene with the corresponding aliphatic aldehydes 14a – c , affording compounds 13a’ – c’ in moderate yields (71%–72%) and enantioselectivities (80%–82% ee ), slightly lower than those of compounds 13a – c . K 2 CO 3 -promoted deprotection of trimethyl group of compounds 13a’ – c’ under mild conditions gave compounds 12a – c in good yields (87%–89%) [ 52 ]. Following the same procedures as shown in Scheme 3 , compounds 6a – c were obtained in moderate yields (81%–83%) and nearly without loss of enantioselectivities (79%–82% ee , the ee values were measured by HPLC after derived by 3,5-dinitrobenzoyl chloride).…”