Preparation and Diels−Alder Reactivity of 1-Amino-3-siloxy-1,3-butadienes

Aza Diels–Alder reactions of sulfinimines with the Rawal diene

“…This diene was developed by Rawal et al in 1997. 10 It was shown that several classes of dienophiles including imines, react easily with the Rawal diene. 11 Herein, we report the use of optically active sulfinimines in this type of reaction.…”

“…Diene 2 was prepared from 4-(dimethylamino)-3-buten-2-one according to an original procedure. 10 The reaction of 10-isobornylsulfinimines 12 1a-e with diene 2 in CH 2 Cl 2 at À70°C gave the expected dihydropyridones 3 in good yields (Scheme 1 and Table 1). …”

“…The Rawal diene was synthesized from 4-(dimethylamino)-3-buten-2-one. 10 Sulfinimines 1a-e, 12,18 1g 19 and 1h 20 were obtained as described in original procedures.…”

Iridium-Catalyzed Enantioselective Allylic Substitution of Enol Silanes from Vinylogous Esters and Amides

“…Compound 5a was then converted into diene 12 with NaHMDS and TBSCl. 2 [4 + 2] Cycloaddition of diene 12 and ethyl propiolate at 50 °C in toluene provided 1,1-diarylalkane 13 in 77% yield from 5a . DIBAL reduction of the ethyl ester of 13 gave alcohol 14 , which was then protected as the bis-TBS ether 15 .…”

“…Danishefsky's diene 1 and Rawal's diene 2 are widely used reagents for Diels–Alder and hetero-Diels–Alder reactions to synthesize carbocycles as well as oxygen- and nitrogen-containing heterocycles. 3 Although both dienes contain an enol silane unit that could undergo nucleophilic substitution reactions, they have rarely been used as nucleophiles for reactions besides [4 + 2] cycloadditions 4 and have not been used as nucleophiles for asymmetric allylic substitutions.…”