Enantioselective synthesis of bicarbocyclic structures with an all-carbon quaternary stereocenter through sequential cross metathesis and intramolecular Rauhut–Currier reaction

Abstract

Enantioselective synthesis of bicarbocyclic structures with an all-carbon quaternary stereocenter through sequential cross metathesis and intramolecular Rauhut-Currier reaction." Tetrahedron Letters 51, no. 19 (2010Letters 51, no. 19 ( ): 2636Letters 51, no. 19 ( -2638

Enantioselective synthesis of decalin structures with all-carbon quaternary centers via one-pot sequential Cope/Rauhut–Currier reaction

“…The current procedure for the synthesis of decalin cores compliments our previous work 16 which generated 6–5 bicarbocyclic structures with Rauhut-Currier reactions. The highly functionalized decalin structure that results from the one-pot sequential Cope/Rauhut-Currier reaction has the potential to be a valuable intermediate in the synthesis of complex bioactive natural products.…”

“…In the case of 1a and 1b , the Cope rearrangement to 2a and 2b occurred in an unoptimized 68 and 35% yield, respectively. Disappointingly, subjecting 2a or 2b to the Rauhut-Currier conditions that we previously reported 16 on similar substrates were unsuccessful. Fortunately, a simple adjustment to a higher boiling alcohol solvent, 2-methyl-1-butanol, and heating the reaction to reflux temperature provided the necessary solution.…”

“…Herein we report a one-pot intramolecular Cope/Rauhut-Currier sequence which illustrates the potential for the efficient enantioselective construction of functionalized decalin structures ( 3 , Scheme 1). Building on the Birch-Cope sequence 13–15 and Rauhut-Currier application 16 that we communicated recently, we now report the ability to conduct the Cope rearrangement and an intramolecular Rauhut-Currier reaction in one pot. There are many tandem reactions involving a Cope rearrangement 1,11,12 and there are also a collection of domino reactions involving the Rauhut-Currier reaction 17–22 , but to the best of our knowledge the two have yet to be combined into a one-pot sequential process.…”

Enantioselective γ-Alkylation of α,β-Unsaturated Malonates and Ketoesters by a Sequential Ir-Catalyzed Asymmetric Allylic Alkylation/Cope Rearrangement

“…3g Alternatively, a Birch–Cope sequence has been developed by the Malachowski group as an efficient method to access γ -alkylated α,β-unsaturated ketoesters, although stoichiometric alkali metals and chiral auxiliaries were required. 4 Despite these reports, a general strategy to selectively produce γ -functionalized unsaturated carbonyl derivatives has remained elusive.…”

“…The rigidity of the transition state plays a key role in enabling the chirality transfer (>99%). 4b It is worth noting that the rearranged γ-alkylation products from the major isomer 7aa and the minor isomer 7aa' ; have opposite absolute configurations (Scheme 5a and 5b). Since the diastereomers 7aa and 7aa' have identical tertiary chiral centers, the outcome of the rearrangement is controlled solely by the quaternary center.…”