Synthesis and Diastereoselective Complexation of Enantiopure Sulfinyl Dienes:  The Preparation of Sulfinyl Iron(0) Dienes

Abstract

The preparation of a diverse array of enantiomerically pure 1- and 2-sulfinyl dienes has been achieved via Stille coupling of halovinyl sulfoxides and vinyl stannanes, hydrogenation of 1-sulfinyl-1-en-3-ynes, or vinylcupration of 1-sulfinyl alkynes. Formation of the corresponding sulfinyl diene iron(0) tricarbonyl complexes was accomplished by utilizing Fe(CO)5/NMO or (bda)Fe(CO)3 as iron(0) tricarbonyl transfer reagents. Installation of the iron(0) tricarbonyl fragment was shown to be highly diastereoselective (10−16:1) for (R)-(1Z)-1-sulfinyl dienes, most likely as a result of allylic 1,3-strain. The synthesis of a 1-sulfinyl-1,3,8,10-tetraene is also described.

Recent developments in chiral non-racemic sulfinyl group chemistry in asymmetric synthesis

“…96 Similar compounds have also been synthesised via Stille coupling of halovinyl sulfoxides, partial hydrogenation of sulfinyl enynes or vinylcupration of sulfinyl alkynes. 97 The formation of the corresponding iron(0) tricarbonyl complexes is also described. Enantiomerically pure hydroxy sulfinyl dienes 127 were prepared from base-induced rearrangement of epoxy vinyl sulfoxides, the E-Z-stereoselectivity being controlled by the chiral sulfur auxiliary.…”

Highly Diastereoselective Diels–Alder Reactions with Enantiopure Sulfinyl‐Substituted 1‐Hydroxymethyldienes

“…Hydroxy-3-sulfinyldienes 1 and 2 were prepared by Stille coupling from the corresponding iodo vinyl sulfoxides. [8] Dienols 1 a-c were selected to evaluate the effect of representative R groups and different Ar substituents on sulfur. Compound 2 was selected to test the influence of the E/Z geometry of the dienol.…”

“…Once all of the starting material had disappeared from the reaction mixture (determined by TLC analysis) the solvent was removed under reduced pressure and the crude product was purified by recrystallization or by column chromatography on silica gel using the appropriate mixture of solvents. (11): Following the general procedure cycloadduct 11 was obtained after 2 h from diene 1 a [8] (10 mg, 0.036 mmol, 1.0 equiv) and PTAD (10 mg 7, 21.6, 22.4, 27.0, 32.8, 52.0, 60.9, 64.8, 122.9, 125.4 (2 C), 125.9 (2 C), 128.6, 129.2 (2 C), 130.6, 130.8 (2 C), 137.9, 143.7, 145.2, 149.7, 154.1 ppm; IR (KBr): ñ = 3421, 3043,2957,2927,2862,1769,1711,1503,1421,1298,1136,1052,811,766 H 6.00, N 9.26, S 7.07; found: C 63.62, H 6.14, N 9.18, S 7.16. (18 a): Following the general procedure cycloadduct 18 a was obtained after five days from diene 3 a [7] (38 mg, 0.12 mmol, 1.0 equiv) and NPM (63 mg, 0.36 mmol, 1.5 equiv) in toluene (1.5 mL).…”

“…After this time, the silica gel was removed by filtration with EtOAc to yield a 25:75 mixture (determined by 1 1 H); NOE between H-1/H-7a: 11.5 %, between H-3 a/H-7a: 11.0 %, between H-3 a/H-4: 11.0 %; 13 C NMR (50 MHz, CDCl 3 ): d = 13. 8,14.0,21.3,21.5,22.3,29.0,33.4,33.5,38.4,40.6,42.0,47.6,82.5,120.1 (2 C),124.5,126.1 (2 C),128.9 (2 C),130.6 (2 C),136.4,138.0,139.4,139.7,143.3,168.9,178.9 ppm;IR (CCl 4 ): ñ = 3300, 3150,2970,2940,2880,1750,1680,1600,1550,1500,1490,1450,1200,1080,1050,1020 476, 444, 391, 354, 285, 243, 217, 174, 139, 123, 93, 91 (100) 9, 20.4, 21.6, 22.4, 27.9, 29.7, 34.0, 34.1, 35.0, 41.2, 41.4, 47.9, 79.0, 119.8 (2 C), 125.1, 126.4 (2 C), 129.1 (2 C), 130.4 (2 C), 133.9, 136.9, 139.3, 140.7, 143.1, 168.8 ppm (2 C); IR (CCl 4 ): ñ = 3340, 3320,2960,2940,2880,1740,1680,1610,…”

“…[6] In recent years, we have been involved in the development of different strategies for the synthesis of the enantiopure hydroxy-3-and -2-sulfinyldienes C and D (Scheme 1). [7,8] Since these routes gave access to substrates with different substitution patterns, we thought it would be interesting to carry out a general study of their Diels-Alder reactivity. [9] Moreover, the synthesis of enantiopure dienes D would provide a unique opportunity to assess the relative p-facial stereodirecting abilities of two powerful elements of stereocontrol in a Diels-Alder process.…”