Biimidazoline ligands for palladium-catalyzed asymmetric allylic alkylation

A practical one-pot method for the synthesis of biimidazoline has been developed. A variety of biimidazolines were prepared smoothly under mild conditions and were evaluated in Pd-catalyzed asymmetric allylic alkylation of 1,3-diaryl-2-propenyl acetate with malonate. The catalytic system gave the desired adducts in good yield and with excellent enantioselectivities (up to 97% ee).

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(4S,4′S)-4,4′-Diisopropyl-1,1′-di-p-tolyl-4,4′,5,5′-tetrahydro-1H,1′H-2,2′-biimidazoleC26H34N4[α]D25 = −257 (c 0.11, CHCl3)Absolute configuration: (4S,4′S)

(4S,4′S)-4,4′-Di-tert-butyl-1,1′-di-p-tolyl-4,4′,5,5′-tetrahydro-1H,1′H-2,2′-biimidazoleC28H38N4[α]D25 = −359 (c 0.10, CHCl3)Absolute configuration: (4S,4′S)

(4S,4′S)-4,4′-Diisopropyl-1,1′-bis(2-methoxyphenyl)-4,4′,5,5′-tetrahydro-1H,1′H-2,2′-biimidazoleC26H34N4O2[α]D25 = −177 (c 0.09, CHCl3)Absolute configuration: (4S,4′S)

(4S,4′S)-4,4′-Di-tert-butyl-1,1′-bis(2-methoxyphenyl)-4,4′,5,5′-tetrahydro-1H,1′H-2,2′-biimidazoleC28H38N4O2[α]D25 = −122 (c 0.10, CHCl3)Absolute configuration: (4S,4′S)

(E)-Dimethyl 2-(1,3-diphenylallyl)malonateC20H20O4[α]D20 = −20 (c 0.107, CH2Cl2)Absolute configuration: not determined

(E)-Dibenzyl 2-(1,3-diphenylallyl)malonateC32H28O4[α]D20 = −8 (c 0.090, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-[1,3-bis(4-fluorophenyl)allyl]malonateC22H22F2O4[α]D20 = −14 (c 0.072, CH2Cl2)Absolute configuration: not determined

(E)-Dimethyl 2-[1,3-bis(4-chlorophenyl)allyl]malonateC20H18Cl2O4[α]D20 = +1 (c 0.138, CH2Cl2)Absolute configuration: not determined

(E)-Dibenzyl 2-[1,3-bis(4-chlorophenyl)allyl]malonateC32H26Cl2O4[α]D20 = +3 (c 0.113, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-[1,3-bis(4-bromophenyl)allyl]malonateC22H22Br2O4[α]D20 = +4 (c 0.158, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-(1,3-diphenylallyl)malonateC22H24O4[α]D20 = −18 (c 0.156, CH2Cl2)Absolute configuration: not determined

(E)-Dimethyl 2-[1,3-bis(4-fluorophenyl)allyl]malonateC20H18F2O4[α]D20 = −16 (c 0.055, CH2Cl2)Absolute configuration: not determined

(E)-Dibenzyl 2-[1,3-bis(4-fluorophenyl)allyl]malonateC32H26F2O4[α]D20 = −6 (c 0.178, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-[1,3-bis(4-chlorophenyl)allyl]malonateC22H22Cl2O4[α]D20 = +1 (c 0.146, CH2Cl2)Absolute configuration: not determined

(E)-Dimethyl 2-[1,3-bis(4-bromophenyl)allyl]malonateC20H18Br2O4[α]D20 = +5 (c 0.124, CH2Cl2)Absolute configuration: not determined

(E)-Dibenzyl 2-[1,3-bis(4-bromophenyl)allyl]malonateC32H26Br2O4[α]D20 = +8 (c 0.109, CH2Cl2)Absolute configuration: not determined

(E)-Dimethyl 2-(1,3-di-o-tolylallyl)malonateC22H24O4[α]D20 = −66 (c 0.120, CH2Cl2)Absolute configuration: not determined

(E)-Dibenzyl 2-(1,3-di-o-tolylallyl)malonateC34H32O4[α]D20 = −32 (c 0.199, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-[1,3-bis(2-chlorophenyl)allyl]malonateC22H22Cl2O4[α]D20 = −9 (c 0.117, CH2Cl2)Absolute configuration: not determined

(E)-Dimethyl 2-[1,3-bis(3-nitrophenyl)allyl]malonateC20H18N2O8[α]D20 = −18 (c 0.121, CH2Cl2)Absolute configuration: not determined

(E)-Dibenzyl 2-[1,3-bis(3-nitrophenyl)allyl]malonateC32H26N2O8[α]D20 = −16 (c 0.124, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-[1,3-bis(3-methoxyphenyl)allyl]malonateC24H28O6[α]D20 = −12 (c 0.122, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-(1,3-di-o-tolylallyl)malonateC24H28O4[α]D20 = −53 (c 0.105, CH2Cl2)Absolute configuration: not determined

(E)-Dimethyl 2-[1,3-bis(2-chlorophenyl)allyl]malonateC20H18Cl2O4[α]D20 = −7 (c 0.104, CH2Cl2)Absolute configuration: not determined

(E)-Dibenzyl 2-[1,3-bis(2-chlorophenyl)allyl]malonateC32H26Cl2O4[α]D20 = −6 (c 0.164, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-[1,3-bis(3-nitrophenyl)allyl]malonateC22H22N2O8[α]D20 = −13 (c 0.110, CH2Cl2)Absolute configuration: not determined

(E)-Dimethyl 2-[1,3-bis(3-methoxyphenyl)allyl]malonateC22H24O6[α]D20 = −16 (c 0.081, CH2Cl2)Absolute configuration: not determined

(E)-Diethyl 2-[1,3-Bbs(3-methoxyphenyl)allyl]malonateC34H32O6[α]D20 = −7 (c 0.112, CH2Cl2)Absolute configuration: not determined