Cascade Arylalkylation of Activated Alkenes: Synthesis of Chloro- and Cyano-Containing Oxindoles

Abstract

The general method for the oxidative cyclization of arylacrylamides with dichloromethane or acetonitrile has been developed. The reactions described provide novel access to chloro- and cyano-containing oxindoles in good to moderate yields that allow the direct formation of a C-C bond and the construction of an oxindole ring in one reaction. The use of a cheap and easily prepared Mn(OAc)3 represents an added advantage of this method.

Oxidative Divergent Bicyclizations of 1,n‐Enynes through α‐C(sp3)–H Functionalization of Alkyl Nitriles

“…For example, Liu and co‐workers have reported the first Pd‐catalyzed oxidative arylalkylation of N ‐arylacrylamides with alkyl nitriles leading to nitrile‐containing oxindoles, in which a combination of PhI(OPiv) 2 oxidant with AgF promoter is the key for achieving oxidative cleavage of one C( sp 3 )−H bond α to the nitrile group (Scheme a) . Subsequently, some groups, including the groups of Zhu,– Gao/You, Zhu, Xu/Ji,, Tang and ours,, have independently developed a conceptually new, radical‐mediated C–H oxidative α‐functionalization of alkyl nitriles by means of difunctionalization of diverse alkenes using peroxide oxidants (Scheme b). However, these transformations are limited to the formation of two new chemical bonds through the addition of one C−H bond α to the nitrile group across the C=C double bond in alkenes followed by termination with a nucleophile (e.g., arenes, amides, acids and alcohols).…”

Reaction Medium as the Installing Reservoir for Key Functionalities in the Molecules

“…CNor . CH 2 CN radicals, either via metals such as Cu/Ag, Cu, Mn, Fe, Pt/TiO 2, or via some metal‐free radical generators such as TBPB . Similarly generation of CN − anion was achieved using various systems such as Cu, NaH .…”

Palladium‐Catalyzed Domino Heck/Phosphorylation towards 3,3‐Disubstituted Phosphinonyloxindoles

“…[6] Meanwhile, transition metalcatalyzed reactions of aryl halides and P(O)À H compounds have proven to be a versatile strategy for the formation of P-arylation products since the development of the Hirao reaction. [8] Owing to our continuous interest in the PÀ C bond construction [9] and ongoing project in the synthesis of functional indoles and oxindoles, [10] we reasoned that oxidative addition of an acrylamide 1 to a Pd(0) species generated in situ gives intermediate A, which undergoes 5-exo-trig cyclization to afford the intermediate alkylpalladium complex B (Scheme 1). [8] Owing to our continuous interest in the PÀ C bond construction [9] and ongoing project in the synthesis of functional indoles and oxindoles, [10] we reasoned that oxidative addition of an acrylamide 1 to a Pd(0) species generated in situ gives intermediate A, which undergoes 5-exo-trig cyclization to afford the intermediate alkylpalladium complex B (Scheme 1).…”

“…(Table 1, entry 5). Subsequently, we checked the effect of various bases and found that a serious decrease in the yield was observed using Cs 2 CO 3 , K 3 PO 4 and Et 3 N, indicating that the choice of base was also crucial for the reaction ( Table 1, entries [10][11][12]. Subsequently, we checked the effect of various bases and found that a serious decrease in the yield was observed using Cs 2 CO 3 , K 3 PO 4 and Et 3 N, indicating that the choice of base was also crucial for the reaction ( Table 1, entries [10][11][12].…”

“…[7] However, no report has appeared using a domino Heck-phosphorylation process to synthesize 3-phosphinomethyl 3,3-disubstituted oxindoles, and may be due to the strong coordinating abilities of both the P(O)À H compounds and products, leading to catalyst deactivation. [8] Owing to our continuous interest in the PÀ C bond construction [9] and ongoing project in the synthesis of functional indoles and oxindoles, [10] we reasoned that oxidative addition of an acrylamide 1 to a Pd(0) species generated in situ gives intermediate A, which undergoes 5-exo-trig cyclization to afford the intermediate alkylpalladium complex B (Scheme 1). It has been established that a Pd(0) complex is spontaneously formed from Pd(II) and phosphine ligands by an irreversible intramolecular reduction of a Pd(II) complex by the phosphine (Scheme 1).…”