High-Pressure-Promoted Diels−Alder Reactions between Cycloalkenones and 3-Methylsulfanylfuran and 3-Phenylsulfanylfuran

Abstract

Keywords: Asymmetric synthesis / Cycloaddition / High-pressure chemistry / Sulfur heterocycles 3-Methylsulfanylfuran and 3-phenylsulfanylfuran were found to undergo facile, regioselective and stereoselective Diels−Alder (DA) cycloaddition to a variety of cycloalkenones under high pressure to give the corresponding ringannulated 7-oxabicyclo[2.2.1]heptene derivatives in good [a] 2869 yields. The vinyl sulfide groups in the adducts were oxidized to relatively stable vinylsulfones, which were utilized for synthetic transformations such as further DA cycloadditions and epoxidation.of both 1 and 2 were evaluated in terms of adduct stability and their further synthetic potential.

Vinylogous Mukaiyama–Michael Reactions between 2‐Silyloxyfurans and Cyclic Enones or Unsaturated Oxo Esters

“…The major anti isomers would then arise from an exo approach ( TS3 ) of the silyloxyfuran to the cyclic enone. Such exo selectivity has previously been observed in studies of high‐pressure‐promoted Diels–Alder reactions involving cycloalkenones and silyloxyfurans11 or 3‐(methylsulfanyl)furan 24. In our case, no Diels–Alder product was observed prior to hydrolysis of the crude mixture with HCl (1 M ).…”

Vinylogous Mukaiyama–Michael Reactions between 2‐Silyloxyfurans and Cyclic Enones or Unsaturated Oxo Esters

“…The major anti isomers would then arise from an exo approach ( TS3 ) of the silyloxyfuran to the cyclic enone. Such exo selectivity has previously been observed in studies of high‐pressure‐promoted Diels–Alder reactions involving cycloalkenones and silyloxyfurans11 or 3‐(methylsulfanyl)furan 24. In our case, no Diels–Alder product was observed prior to hydrolysis of the crude mixture with HCl (1 M ).…”

High pressure in organic chemistry on the way to miniaturization

“…95,100 Under high pressure (11-15 kbar), 3-methyl-and 3-phenylsulfanylfuran ( 14) undergo a facile, regioselective, and stereoselective Diels-Alder cycloaddition reaction with a variety of cycloalkenones (e.g., 15) to give the corresponding annulated 7oxabicyclo[2.2.1]heptene derivatives (16) in good yields (Scheme 5) using zinc iodide as catalyst. 101 More examples of Diels-Alder reactions affected by high pressure, when catalysts are involved, are summarized in several papers. [102][103][104][105][106][107][108][109] Other researchers have used high pressure for the synthesis of Diels-Alder cycloadducts in a regio-and stereoselective manner.…”

High pressure: a challenge for lab-on-a-chip technology

“…15) to give the corresponding annulated 7oxabicyclo[2.2.1]-heptene derivatives (16) in good yields (Scheme 2-5) using zinc iodide as catalyst. 123 More examples of Diels-Alder reactions affected by high pressure, when catalysts are involved, are summarized in references 124-131. Others have used high pressure for the synthesis of Diels-Alder cycloadducts in a regio-and stereoselective way.…”

Vinylogous Mukaiyama–Michael Reactions between 2‐Silyloxyfurans and Cyclic Enones or Unsaturated Oxo Esters

“…The major anti isomers would then arise from an exo approach ( TS3 ) of the silyloxyfuran to the cyclic enone. Such exo selectivity has previously been observed in studies of high‐pressure‐promoted Diels–Alder reactions involving cycloalkenones and silyloxyfurans11 or 3‐(methylsulfanyl)furan 24. In our case, no Diels–Alder product was observed prior to hydrolysis of the crude mixture with HCl (1 M ).…”

High pressure in organic chemistry on the way to miniaturization

“…95,100 Under high pressure (11-15 kbar), 3-methyl-and 3-phenylsulfanylfuran ( 14) undergo a facile, regioselective, and stereoselective Diels-Alder cycloaddition reaction with a variety of cycloalkenones (e.g., 15) to give the corresponding annulated 7oxabicyclo[2.2.1]heptene derivatives (16) in good yields (Scheme 5) using zinc iodide as catalyst. 101 More examples of Diels-Alder reactions affected by high pressure, when catalysts are involved, are summarized in several papers. [102][103][104][105][106][107][108][109] Other researchers have used high pressure for the synthesis of Diels-Alder cycloadducts in a regio-and stereoselective manner.…”

High pressure: a challenge for lab-on-a-chip technology

“…15) to give the corresponding annulated 7oxabicyclo[2.2.1]-heptene derivatives (16) in good yields (Scheme 2-5) using zinc iodide as catalyst. 123 More examples of Diels-Alder reactions affected by high pressure, when catalysts are involved, are summarized in references 124-131. Others have used high pressure for the synthesis of Diels-Alder cycloadducts in a regio-and stereoselective way.…”

Vinylogous Mukaiyama–Michael Reactions between 2‐Silyloxyfurans and Cyclic Enones or Unsaturated Oxo Esters

“…The major anti isomers would then arise from an exo approach ( TS3 ) of the silyloxyfuran to the cyclic enone. Such exo selectivity has previously been observed in studies of high‐pressure‐promoted Diels–Alder reactions involving cycloalkenones and silyloxyfurans11 or 3‐(methylsulfanyl)furan 24. In our case, no Diels–Alder product was observed prior to hydrolysis of the crude mixture with HCl (1 M ).…”

High pressure in organic chemistry on the way to miniaturization

“…95,100 Under high pressure (11-15 kbar), 3-methyl-and 3-phenylsulfanylfuran ( 14) undergo a facile, regioselective, and stereoselective Diels-Alder cycloaddition reaction with a variety of cycloalkenones (e.g., 15) to give the corresponding annulated 7oxabicyclo[2.2.1]heptene derivatives (16) in good yields (Scheme 5) using zinc iodide as catalyst. 101 More examples of Diels-Alder reactions affected by high pressure, when catalysts are involved, are summarized in several papers. [102][103][104][105][106][107][108][109] Other researchers have used high pressure for the synthesis of Diels-Alder cycloadducts in a regio-and stereoselective manner.…”

High pressure: a challenge for lab-on-a-chip technology

“…15) to give the corresponding annulated 7oxabicyclo[2.2.1]-heptene derivatives (16) in good yields (Scheme 2-5) using zinc iodide as catalyst. 123 More examples of Diels-Alder reactions affected by high pressure, when catalysts are involved, are summarized in references 124-131. Others have used high pressure for the synthesis of Diels-Alder cycloadducts in a regio-and stereoselective way.…”