Copper‐Catalyzed Asymmetric Conjugate Addition of Aryl Aluminum Reagents to Trisubstituted Enones: Construction of Aryl‐Substituted Quaternary Centers

Abstract

In the typical procedure in the Experimental Section of this paper (see also the Supporting Information), the first sentence should read: "The aryl iodide (1.05 mmol) was dissolved in Et 2 O (0.5 mL) under an inert atmosphere and cooled to À55 8C before the addition of nBuLi (1.05 mmol, 656 mL, 1.6 m in hexanes)." The authors apologize for the oversight.

Aluminum Bases for the Highly Chemoselective Preparation of Aryl and Heteroaryl Aluminum Compounds

“…[20] However, the metalation of 2,3-dihydrobenzofuran (11) with 4 proceeded smoothly within 12 h at 25 8C, and a palladium-catalyzed cross-coupling reaction furnished the compound 12 in 85 % yield (Scheme 3). Furthermore, the treatment of benzo- [1,3]dioxole (13 a) or benzo [1,4] In conclusion, we have reported a new directed alumination that enables the regioselective functionalization of various aromatic and heteroaromatic compounds. A number of functional groups are tolerated, including ester and cyano groups, as well as halogen atoms.…”

“…The Lewis acidic character of the aluminum metal center enables reactions with unique chemo-, regio-, and enantioselectivity to be carried out. [2,3] In general, aryl aluminum species are generated by transmetalation of aryl lithium reagents with various aluminum(III) sources [4] or in some cases through aluminum-tin or aluminum-boron exchange reactions.[5] The deprotonation of aromatic rings with an aluminum base is a very convenient method for the preparation of unsaturated organoaluminum compounds. Recently, Uchiyama, Wheatley, and co-workers reported directed alumination reactions with the powerful aluminate base iBu 3 Al(TMP)Li (TMP = 2,2,6,6-tetramethylpiperidyl).…”

Synthesis of diverse β-quaternary ketones via palladium-catalyzed asymmetric conjugate addition of arylboronic acids to cyclic enones

“…1 Historically, the 1,4 addition of a nucleophile to a suitable α,β-unsaturated conjugate acceptor has been a reliable means of synthesizing these challenging quaternary stereocenters. 2 Many groups have pioneered methods for this transformation employing highly reactive organometallic reagents (e.g., diorganozinc, 3 triorganoaluminum, 4 and organomagnesium reagents 5 ) to react with a large array of electrophiles under copper catalysis. Rigorously anhydrous conditions are a requirement of these approaches, as they uniformly utilize water-sensitive reagents.…”

Enantioselective One‐Pot Conjugate Addition of Grignard Reagents Followed by a Mannich Reaction

“…[7] Especially copper-catalyzed additions of dialkylzinc, [8] Grignard reagents, [9] organoaluminium reagents, [10] or conjugate reduction [11] produce reactive metal enolates. Such functionalized enolates are often inaccessible by other means.…”