Formation of Carbocycles via a 1,4-Rh Shift Triggered by a Rhodium-Catalyzed Addition of Terminal Alkynes to 3,3-Diarylcyclopropenes

Abstract

The catalytic addition of terminal alkynes to 3,3-diarylcyclopropenes in the presence of a Rh(I)/binap complex proceeded to give the cycloaddition products in good yields, where a 1,4-Rh shift is involved as a key step.

1,4‐Migration of Transition Metals in Organic Synthesis

“…The addition of Rh‐alkynyl species to cyclopropenes gave M117 , which underwent a 1,4‐Rh shift from cyclopropyl to aryl. Intramolecular insertion in the triple bond to C(aryl)‐Rh of M118 delivered M119 , which gave the final rearranged product 126 via protonation (Scheme ) …”

Recent Advances of Cyclopropene Chemistry

“…利用亲核试剂对环丙烯双键加成已成为合成多取 代环丙烷最简单的方法之一, 其中, 在金属催化下环丙 烯炔基化生成环丙基炔化物的报道也有很多. 2015 年, Nishimura 报道了 3,3-二芳基环丙烯在 Rh 的催化下与炔 的加成反应 [57] . 该反应最终生成多元碳环化合物经历 Figure 62 Selective labeling of CpK-encoded myoglobin using photoclick chemistry 同一年, Prescher 也将环丙烯用作了生物正交化学 反应官能团 [59] .…”

Asymmetric Conjugate Alkynylation of Cyclic α,β‐Unsaturated Carbonyl Compounds with a Chiral Diene Rhodium Catalyst

“…Thecatalytic asymmetric conjugate alkynylation has been reported with nickel, [3] copper, [4] rhodium, [5][6][7][8] and other metal [9] complexes as catalysts.A lthough high yields and high enantioselectivities have been reported for some of acyclic a,b-unsaturated carbonyl compounds,t here have been only af ew reports on successful asymmetric alkynylation of cyclic substrates,t ypically 2-cyclohexenone and 2-cyclopentenone.O ne of them is the nickel-catalyzed addition of alkynylaluminum reagents reported by Corey and co-workers,w herein 3-alkynylcyclohexanones were obtained with 85-90 % ee. The rhodium catalyst system consisting of DTBM-segphos and (triisopropylsilyl)acetylenel ed to high yields and high enantioselectivities for acyclic a,b-unsaturated ketones,t ypically 1-phenylbut-2-en-1-one and some other reactive substrates, [6] but it is not applicable to less reactive cyclic enones because the alkynylrhodium intermediate with the very bulky ligand, DTBM-segphos,i sn ot reactive toward the cyclic enones (Scheme 1a). The rhodium catalyst system consisting of DTBM-segphos and (triisopropylsilyl)acetylenel ed to high yields and high enantioselectivities for acyclic a,b-unsaturated ketones,t ypically 1-phenylbut-2-en-1-one and some other reactive substrates, [6] but it is not applicable to less reactive cyclic enones because the alkynylrhodium intermediate with the very bulky ligand, DTBM-segphos,i sn ot reactive toward the cyclic enones (Scheme 1a).…”

“…[1] While an umber of efficient reaction systems have been reported on the asymmetric conjugate addition of sp 3 -a nd sp 2 -carbon nucleophiles by use of chiral metal catalysts and organocatalysts, [2] thed evelopment has been slow on the asymmetric introduction of sp-carbon atoms (alkynyl groups). Thecatalytic asymmetric conjugate alkynylation has been reported with nickel, [3] copper, [4] rhodium, [5][6][7][8] and other metal [9] complexes as catalysts.A lthough high yields and high enantioselectivities have been reported for some of acyclic a,b-unsaturated carbonyl compounds,t here have been only af ew reports on successful asymmetric alkynylation of cyclic substrates,t ypically 2-cyclohexenone and 2-cyclopentenone.O ne of them is the nickel-catalyzed addition of alkynylaluminum reagents reported by Corey and co-workers,w herein 3-alkynylcyclohexanones were obtained with 85-90 % ee. [3] We have previously reported rhodium-catalyzed asymmetric addition of (triisopropylsilyl)acetylenet oa,b-unsaturated ketones, [5] where the main side-reaction forming the acetylene dimer [10] was suppressed by use of ab ulky chiral bis(phosphine) ligand, DTBM-segphos (Scheme 1a).…”

“…[3] We have previously reported rhodium-catalyzed asymmetric addition of (triisopropylsilyl)acetylenet oa,b-unsaturated ketones, [5] where the main side-reaction forming the acetylene dimer [10] was suppressed by use of ab ulky chiral bis(phosphine) ligand, DTBM-segphos (Scheme 1a). The rhodium catalyst system consisting of DTBM-segphos and (triisopropylsilyl)acetylenel ed to high yields and high enantioselectivities for acyclic a,b-unsaturated ketones,t ypically 1-phenylbut-2-en-1-one and some other reactive substrates, [6] but it is not applicable to less reactive cyclic enones because the alkynylrhodium intermediate with the very bulky ligand, DTBM-segphos,i sn ot reactive toward the cyclic enones (Scheme 1a). Use of alkynylsilanol as an alkynylating reagent and appropriate chiral ligands improved the yield and enantioselectivity for both acyclic and cyclic enones [7,8] (Scheme 1b), but it still has drawbacks in that an excess amount of the alkynylating reagent must be used for ah igh chemical yield and, more importantly,t he substrate scope is not broad.…”